Substrate processing apparatus and substrate processing method

ABSTRACT

On top of respective areas divided by partition plates, that is, a cassette station, a processing station, and an interface section in a coating and developing processing system, gas supply sections for supplying an inert gas into the respective areas are provided. Exhaust pipes for exhausting atmospheres in the respective areas are provided at the bottom of the respective areas. The atmospheres in the respective areas are maintained in a clean condition by supplying the inert gas not containing impurities such as oxygen and fine particles from the respective gas supply sections into the respective areas and exhausting the atmospheres in the respective areas from the exhaust pipes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate processing apparatus and asubstrate processing method for performing coating processing of aresist solution or developing processing, for example, for a substratesuch as a semiconductor wafer, a glass substrate for a liquid crystaldisplay, or the like.

2. Description of the Related Art

In a photolithography process in the process of fabricating asemiconductor device, for example, resist coating processing of forminga resist film on the surface of a wafer, exposure processing of exposingthe wafer by irradiating a pattern on the wafer, developing processingof developing the exposed wafer, heating processing and coolingprocessing before the coating processing, before and after the exposureprocessing, and after the developing processing, and the like areperformed. Such processing is performed in processing units providedindividually, and these processing units are unified to compose acoating and developing processing system so as to continuously performsuch successive processing.

Generally, the coating and developing processing system is composed of aloader/unloader section for carrying a wafer into/out of the coating anddeveloping processing system, a processing section having a coatingprocessing unit, a developing processing unit, a thermal processingunit, and the like and performing the majority of the aforesaid waferprocessing, an aligner outside the system for subjecting the wafer toexposure processing, and an interface section, provided adjacent to theprocessing section and the aligner, for delivering the wafer between theprocessing section and the aligner.

When the wafer is processed in this coating and developing processingsystem, in order to prevent impurities such as fine particles fromadhering to the wafer, air cleaned by an air purifier or the like issupplied as down-flowing air into the coating and developing processingsystem, while an atmosphere inside the coating and developing system isexhausted, whereby the wafer can be processed in a clean condition.

Moreover, to realize sensitive exposure, a chemically amplified resistis used. The chemically amplified resist has a basic polymer insolublein an alkaline developing solution, for example, and an acid generator,and obtains high resolution by causing polarity changes in an exposedportion and an unexposed portion by the use of a catalytic reaction ofan acid. In the aligner, a circuit pattern is exposed in a resist filmby using a mask, and an elimination reaction is caused to a protectivegroup which protects a hydroxyl group of the basic polymer by the acidproduced at this time. Thereafter, the wafer is transferred to thethermal processing unit, where the catalytic reaction of the acid isaccelerated to quicken the elimination reaction by PEB (post-exposurebaking) which is heating after exposure, and thereby the exposedportion, for example, is made soluble in the alkaline developingsolution. The wafer is then transferred to the developing processingunit and the portion which is made soluble is removed by the developingsolution, whereby a precise circuit patter is obtained.

In recent years, however, exposure technology in which a beam with ashorter wavelength is used is being developed to form a finer and moreprecise circuit pattern, and when the beam with the shorter wavelengthis used, it is confirmed that impurities at molecular level such asoxygen, basic substances, ozone, and vapor which have been insignificantso far exert a bad influence on the formation of the precise circuitpattern. Specially when the impurities adhere to the wafer on theoccasion of exposure, an appropriate pattern is not exposed, and thus adrop in yield can not be avoided.

Accordingly, it is necessary for the impurities not to adhere to thewafer under processing, but the use of clean air as before isinappropriate because the air itself contains impurities such as oxygen.

An acid produced at the time of exposure has high reactivity, and henceshows a neutralization reaction with basic substances in air during thetransfer of the wafer. In this case, the acid is deactivated, whichcauses a change in the formation of a slightly soluble surface layer andthe line width of the circuit pattern. The elimination reaction of aprotective group depends on the temperature, and some kind of chemicallyamplified resist causes the elimination reaction of the productive baseby a catalytic reaction of the acid, for example, even in the state ofan ordinary temperature. Therefore, there is the possibility that theelimination reaction progresses during transfer before PEB, which causespattern deformation, the deterioration of reproducibility, and the like.

Even in such pattern deformation as can be conventionally ignored, thereis still room for improvement in these days when a more precise circuitpattern is demanded, but such clean air and system configuration asbefore can not meet the demand.

Moreover, the wafer comes and goes between the processing section andthe exposure processing section via the interface section. There is thepossibility that the neutralization reaction of the acid or theelimination reaction of the productive base occur after exposure asdescribed above, while the acid is not produced before exposure, andconsequently the conditions of an atmosphere inside the interfacesection demanded before and after exposure are different. Thus, theformation of the optimum atmosphere for the condition of the wafer afterexposure in the interface section is demanded.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a substrate processingapparatus and a substrate processing method capable of preventing fineimpurities at molecular level from adhering to a substrate such as awafer or the like.

Another object of the present invention is to provide a substrateprocessing apparatus and a substrate processing method capable ofpreventing fine impurities at molecular level from adhering to asubstrate such as a wafer or the like and individually controllingatmospheres in substrate routes before and after exposure in aninterface section to prevent acid deactivation, pattern deformation, andthe like.

Still another object of the present invention is to provide a substrateprocessing apparatus and a substrate processing method capable ofimproving the uniformity of developing line width in a surface of asubstrate and between substrates by transferring the exposed substrateto a heating section while inhibiting the progress of a resolutionreaction of a resist and performing heating processing there.

To attain the aforesaid objects, according to the present invention, acoating and developing processing system, which is a system forperforming coating and developing processing for a substrate andcharacterized by comprising a loader/unloader section for carrying thesubstrate into/out of the system; a processing section having a coatingprocessing unit for at least forming a coating film on the substrate, adeveloping processing unit for developing the substrate, a thermalprocessing unit for thermally processing the substrate, and a firsttransfer device for carrying the substrate into/out of the coatingprocessing unit, the developing processing unit, and the thermalprocessing unit; an interface section having a second transfer devicefor transferring the substrate at least via a route between theprocessing section and an aligner for subjecting the substrate toexposure processing; a gas supply device for supplying an inert gas tothe interface section; and an exhaust means for exhausting an atmospherein the interface section in a casing of this system, is provided.Incidentally, the thermal processing unit includes a heating processingunit, a cooling processing unit, and a heating/cooling processing unit,and the like. Further, the processing section may include otherprocessing units such as an extension unit for making the substrate waitand an adhesion unit for supplying a predetermined processing solutiononto the substrate in order to enhance adhesion properties of thesubstrate and a coating solution.

The aforesaid supply of the inert gas to the interface section by thegas supply device and exhaust of the atmosphere in the interface sectionby the exhaust means enable the removal of impurities such as oxygen andvapor from within the interface section and the maintenance of theatmosphere inside the interface section in a clean condition.Consequently, the adhesion of impurities to the substrate is suppressed,whereby the substrate is processed suitably. Especially, if impuritiesadhere to the substrate when the substrate undergoes exposureprocessing, the impurities absorb energy of a laser beam and so on usedin exposure, and as a result, the exposure processing is not performedsuitably. Accordingly, it is important to maintain the interfacesection, which the substrate passes through immediately before theexposure processing, in a clean condition. It should be mentioned thatthe aforesaid inert gas is an inert gas for a processing solution usedin the coating and developing processing system, for example, a coatingsolution such as a resist solution, and a developing solution, and a gasnot containing oxygen, moisture, and organic substances, for example,nitrogen gas, argon, neon, or the like.

In the present invention, the system may comprise: a gas supply devicefor supplying the inert gas to an area having at least the thermalprocessing unit and the first transfer device in the processing section;and an exhaust means for exhausting an atmosphere at least in the area.

The aforesaid supply of the inert gas into the processing section inaddition to the interface section enables the removal of impurities suchas oxygen from within the processing section and the maintenance of theatmosphere inside the processing section in a clean condition, resultingin suppression of adhesion of the impurities to the substrate.Especially after a coating film is formed on the substrate and thesubstrate is subjected to heating processing, impurities are apt toadhere to the surface of the substrate. If impurities adhere in thiscase, exposure processing to be performed immediately after this can notbe performed suitably. Hence, the removal of impurities from the surfaceof the substrate in the processing section is important. Incidentally,although the inert gas may be supplied at least into the aforesaid areain the processing section, it also may be supplied into an area otherthan the aforesaid area in the processing section, that is, an areawhere the coating processing unit and the developing processing unit areplaced.

Further, in the present invention, the system may comprise: a gas supplydevice for supplying the inert gas to the loader/unloader section; andan exhaust means for exhausting an atmosphere in the loader/unloadersection.

As described above, also in the loader/unloader section, the substratecan be more perfectly protected from impurities such as oxygen bysupplying the inert gas thereto and maintaining the loader/unloadersection in a clean condition as in the interface section and the area inthe processing section.

The coating and developing processing system described so far maycomprise a partition plate shutting off the atmosphere in the interfacesection from the atmosphere in the processing section, the partitionplate may have a transit opening for delivering the substrate betweenthe area in the processing section and the interface section, and thetransit opening may have a shutter allowing the transit opening tofreely open and close.

By dividing the interface section and the processing section by thepartition plate as described above, the flow of the atmosphere insidethe processing section into the interface section which is maintained ina clean condition thanks to the aforesaid supply of the inert gas can besuppressed. Moreover, by providing the transit opening in the partitionplate and freely opening and closing the transit port by the shutter,the shutter can be opened only when the substrate is delivered betweenthe interface section and the area in the processing section, which canprevent the mutual interference of the atmospheres in the processingsection and the interface section and keep the atmosphere in theinterface section clean. The reason why the position of the transitopening is limited to the partition plate in the area in the processingsection is that the substrate is never transferred directly from anyarea other than the area in the processing section, that is, an areahaving the coating processing unit and the developing processing unit tothe interface section.

Furthermore, in the present invention, the system may comprise anotherpartition plate shutting off the atmosphere in the processing sectionfrom the atmosphere in the loader/unloader section, the aforesaidanother partition plate may have another transit opening for deliveringthe substrate between the area in the processing section and theloader/unloader section, and the aforesaid another transit opening mayhave another shutter allowing the aforesaid another transit opening tofreely open and close.

The aforesaid provision of the partition plate also between theprocessing section and the loader/unloader section and provision of thetransit opening and the shutter for delivering the substrate between thearea in the processing section and the loader/unloader section in thepartition plate make it possible to suppress the interference of theatmospheres in the processing section and the loader/unloader sectionand maintain a predetermined atmosphere in the processing section.Especially, when the inert gas is supplied to the processing section asin claim 2, the flow of the relatively unclean atmosphere inside theloader/unloader section into the processing section is prevented,whereby the atmosphere in the processing section is maintained in aclean condition, and thus the adhesion of impurities to the substrate issuppressed.

In the coating and developing processing system described so far, it issuitable to clean at least a part of the atmosphere exhausted by theexhaust means and send the same as the inert gas to the gas supplydevice again. The aforesaid reuse of the atmosphere exhausted by theexhaust means in the gas supply device as the inert gas can reduce theamount of the inert gas newly required, leading to a reduction in theamount of the inert gas.

In the present invention, the system may comprise a temperatureregulating means for regulating a temperature of the inert gas. Thisprovision of the temperature regulating means makes it possible tomaintain the atmosphere in the coating and developing processing systemto which the inert gas is supplied at a predetermined temperature,whereby the processing, transfer, and the like of the substrate can beperformed in the atmosphere at the predetermined temperature.

Moreover, in the present invention, it is more preferable that thepressure inside the interface section be set lower than the pressureinside the aligner.

The aforesaid setting of the pressure inside the interface section lowerthan the pressure inside the aligner can prevent the atmosphere in theinterface section from flowing into the aligner. Hence, exposureprocessing for the substrate in the aligner is performed suitably in apredetermined atmosphere.

In the present invention, the pressure inside the interface section maybe set lower than the pressure inside the area in the processingsection. The aforesaid setting of the pressure inside the interfacesection lower than the pressure inside the area in the processingsection can prevent the atmosphere in the interface section from flowinginto the area in the processing section. Hence, a predeterminedatmosphere is maintained in the processing section in which substrateprocessing units are provided and a variety of substrate processing isperformed, and the variety of substrate processing can be performedsuitably.

Further, in the present invention, the pressure inside the area in theprocessing section may be set higher than the pressure inside theloader/unloader section. The aforesaid setting of the pressure insidethe area in the processing section higher than the pressure inside theloader/unloader section can prevent the flow of the atmosphere insidethe loader/unloader section into the area in the processing section.Hence, similarly to the above, a predetermined atmosphere is maintainedin the area in the processing section, and thus the variety of substrateprocessing can be performed suitably.

Furthermore, in the present invention, the pressure inside the area inthe processing section may be set lower than the pressures inside thecoating processing unit and the developing processing unit in theprocessing section. The aforesaid setting of the pressure inside thearea in the processing section lower than the pressures inside thecoating processing unit and the developing processing unit can preventatmospheres in the coating processing unit and the developing processingunit from flowing into the area. Accordingly, the coating processingunit or the like in which the atmosphere is controlled more severelythan the processing units such as a predetermined atmosphere ismaintained in the thermal processing unit in the area, and thus coatingprocessing and developing processing which are most important in thiscoating and developing processing can be performed suitably.

In the coating and developing processing system described thus far, thepressure inside the casing is set higher than the pressure outside thecoating and developing processing system. By setting the pressure insidethe casing higher than the pressure outside the coating and developingprocessing system as described above, the flow of an atmosphere outsidethe coating and developing processing system into the casing isprevented. Therefore, the contamination of an atmosphere inside thecasing where the substrate is processed by the relatively dirtyatmosphere outside the coating and developing processing system can besuppressed. It should be noted that the pressure outside the coating anddeveloping processing system means the pressure inside a room where thecoating and developing processing system is installed, for example, thepressure inside a clean room.

The present invention according to another aspect provides a coating anddeveloping system, which is a system for performing coating anddeveloping processing provided with: a processing section having acoating processing unit for at least forming a coating film on asubstrate, a developing processing unit for developing the substrate, athermal processing unit for thermally processing the substrate, and asubstrate transfer device for carrying the substrate into/out of thecoating processing unit, the developing processing unit, and the thermalprocessing unit; and an interface section for transferring the substratevia a route between the processing section and an aligner for subjectingthe substrate to exposure processing, inside the casing, andcharacterized in that a first thermal processing unit for thermallyprocessing the substrate before exposure, a first transfer device fortransferring the substrate before exposure, a second thermal processingunit for thermally processing the substrate after exposure, and a secondtransfer device for transferring the substrate after exposure arearranged in the interface section, and that a first gas supply devicefor supplying an inert gas to an area before exposure having the firstthermal processing unit and the first transfer device in the interfacesection, a first exhaust means for exhausting an atmosphere in the areabefore exposure, a second gas supply device for supplying the inert gasto an area after exposure having the second thermal processing unit andthe second transfer device in the interface section, and a secondexhaust means for exhausting an atmosphere in the area after exposureare provided. Incidentally, the thermal processing unit, the firstthermal processing unit, and the second thermal processing unit includea heating processing unit, a cooling processing unit, a heating/coolingprocessing unit, and the like. Further, the processing section mayinclude other processing units such as an extension unit for making thesubstrate wait and an adhesion unit for supplying a predeterminedprocessing solution onto the substrate in order to enhance adhesionproperties of the substrate and a coating solution.

According to the present invention, in the interface section, bysupplying the inert gas to the area before exposure by the first gassupply device and exhausting the atmosphere in this area before exposureby the first exhaust means, impurities such as oxygen and vapor can beremoved from within the area before exposure, and the area beforeexposure can be maintained in a clean condition. Consequently, thesubstrate can be transferred in a clean atmosphere from heatingprocessing immediately before exposure processing to exposureprocessing, whereby the adhesion of impurities can be prevented.Especially, after the substrate on which a coating film is formed issubjected to heating processing, impurities are apt to adhere to thesurface of the substrate. Moreover, if impurities adhere to thesubstrate when the substrate undergoes exposure processing, theimpurities absorb energy of a laser beam and so on used in exposure, andas a result, there is the possibility that the exposure processing isnot performed suitably. But, by maintaining the area before exposure inthe interface section, which the substrate passes through immediatelybefore the exposure processing, in a clean condition, the substrate canbe processed suitably. It should be mentioned that the aforesaid inertgas is an inert gas for a processing solution used in the coating anddeveloping processing system, for example, a coating solution and adeveloping solution, and a gas not containing oxygen, moisture, andorganic substances, for example, nitrogen gas, argon, neon, or the like.

Moreover, by supplying the inert gas to the area after exposure by thesecond gas supply device and exhausting the atmosphere in this areaafter exposure by the second exhaust means, the area after exposure canbe maintained in a clean condition similarly to the area beforeexposure. Especially when a chemically amplified resist which forms acircuit pattern on the substrate by a catalytic reaction of an acid isused, the acid is deactivated if impurities adheres to the substrateafter exposure processing. But, the aforesaid maintenance of the areaafter exposure in the interface section, which the substrate passesthrough immediately after the exposure processing, in a clean conditioncan prevent the acid deactivation, leading to suitable performance ofthe subsequent developing processing.

The inert gas is supplied to each of the areas by the individual gassupply device, whereby atmospheres peculiar to the respective areas canbe maintained in the areas before exposure and after exposure.

Since the peculiar atmospheres can be maintained in the respectiveareas, the second gas supply device may supply the inert gas having atemperature lower than the temperature of the inert gas to be suppliedby the first gas supply device, or may supply the inert gas having a lowoxygen concentration as described in claim 15.

When the first gas supply device supplies, for example, the inert gashaving an ordinary temperature to the area before exposure, the secondgas supply device supplies the inert gas having a temperature lower thanthe ordinary temperature, whereby the atmosphere in the area afterexposure can be maintained in a low-temperature condition. Especiallywhen the aforesaid chemically amplified resist has a property such thata protective group which protects a hydroxyl group of a basic polymereven at the ordinary temperature shows an elimination reaction, theelimination reaction of the protective group progresses on the substrateduring its transfer within the area after exposure if the temperature ofthe atmosphere in the area after exposure is higher than the ordinarytemperature. The maintenance of the area after exposure in alow-temperature condition, however, can inhibit the elimination reactionof the protective group during transfer. Hence, a circuit pattern can besatisfactorily formed. Moreover, the supply of the inert gas having alow oxygen concentration by the second gas supply device makes itpossible to keep the concentration of oxygen in the atmosphere in thearea after exposure low, which can prevent acid deactivation.

In the present invention, a partition plate shutting off the atmospherein the area before exposure from the atmosphere in the area afterexposure can be provided.

According to the present invention, the partition plate shuts off thearea before exposure from the area after exposure in the interfacesection, which can prevent the mutual interference of the atmospheres,resulting in the maintenance of atmospheres peculiar to the respectiveareas in the areas before and after exposure. Specially when the areaafter exposure is maintained at the low temperature, it is effective toprovide a partition plate between the areas as described above.

In the present invention, the system may have another partition plateshutting off an atmosphere in the processing section from an atmospherein the interface section, the aforesaid another partition plate may havea first transit opening for delivering the substrate between theprocessing section and the area before exposure and a second transitopening for delivering the substrate between the processing section andthe area after exposure, the first transit opening may have a firstshutter allowing the first transit opening to freely open and close, andthe second transit opening may have a second shutter allowing the secondtransit opening to freely open and close.

According to the present invention, by dividing the processing sectionand the interface section by another partition plate, the flow of theatmosphere inside the processing section into the areas before and afterexposure in the interface section maintained in a clean condition by theaforesaid supply of the inert gas can be prevented. Further, theprovision of the first shutter which can freely open and close at thefirst transit opening, for example, makes it possible to open the firstshutter and let the substrate pass only when the substrate is deliveredfrom the processing section to the area before exposure. Furthermore,the provision of the second shutter which can freely open and close atthe second transit opening makes it possible to open the second shutterand let the substrate pass only when the substrate is delivered from thearea after exposure to the processing section. Accordingly, the mutualinterference of the atmospheres in the processing section and theinterface section can be prevented, and the areas before and afterexposure in the interface section can be maintained clean.

In the present invention, the temperature of the inert gas may beregulated. This regulation of the inert gas at a predeterminedtemperature allows atmospheres in respective areas to which the inertgas is supplied to be maintained at the predetermined temperature.

In the present invention, it is desirable to set the pressure in theinterface section lower than the pressure in the aligner. According tosuch a structure, the flow of the atmospheres in the areas before andafter exposure in the interface section into the aligner in which theatmosphere is severely controlled can be prevented by setting thepressure in the interface section lower than the pressure in thealigner.

A substrate processing apparatus of the present invention according tostill another aspect comprises: a processing section for performingcoating and developing processing for a substrate; an interface sectionfor transferring the substrate at least via a route between theprocessing section and an aligner for subjecting the substrate toexposure processing; a chamber, disposed inside the interface section,for temporarily holding the substrate delivered from the processingsection and to be transferred to the aligner; and an atmospherecontroller for controlling an atmosphere in the chamber.

In the present invention, since the substrate delivered from theprocessing section and to be transferred to the aligner is temporarilyheld in the chamber in which the atmosphere is controlled, for example,the variation with time of the resist before exposure can be suppressed,and a change in the property of the resist can be prevented. As aresult, the uniformity of line width can be raised.

The atmosphere controller here reduces the pressure inside the chamberand supplies an inert gas or dry air into the chamber.

The chamber can be structured to comprise: a purge room for temporarilyholding and purging the substrate introduced into the chamber; a bufferroom for holding the substrate; and a transfer device for transferringthe substrate between the purge room and the buffer room. Incidentally,it is desirable that the buffer room have a transit opening for directlycarrying out the substrate to the aligner.

A substrate processing apparatus of the present invention according toanother aspect comprises: a coating processing unit for at least forminga coating film on a substrate; a developing processing unit fordeveloping the substrate; a thermal processing unit for thermallyprocessing the substrate; a transfer device for carrying the substrateinto/out of the coating processing unit, the developing processing unit,and the thermal processing unit; and a blower for sending an inert gasto the substrate which is being transferred by the transfer device.

In the present invention, the blower for sending the inert gas to thesubstrate which is being transferred by the transfer device is provided,which eliminates influence on pattern resolution, for example, due tothe occurrence of hydrolysis of the resist caused by moisture inatmospheric air during the transfer of the substrate afterresist-coating and the bonding of the resist with oxygen in theatmospheric air.

Specifically, for example, the transfer device has tweezers for holdingthe substrate, and the blower has a top cover having a blast port forsending the inert gas from above the tweezers. In this case, a pluralityof the blast ports may be provided to correspond to the shape of thetweezers, or may be provided to correspond to the shape of thesubstrate. The blower may be structured to have a temperature controlmechanism for controlling the temperature of the inert gas or a humiditycontrol mechanism for controlling the humidity of the inert gas.Incidentally, it is most efficient that the blower sends the inert gaswhen the transfer device transfers the substrate from the coatingprocessing unit to the thermal processing unit.

A substrate processing apparatus of the present invention according tostill another aspect is characterized by comprising: a reactioninhibiting section for performing processing of inhibiting the progressof a resolution reaction of a resist for a substrate coated with theresist and exposed; a heating section for heating the substrateprocessed in the reaction inhibiting section to progress the resolutionreaction of the resist; a cooling section for cooling the substrateheated in the heating section to inhibit the progress of the resolutionreaction of the resist; and a developing processing section forperforming coating processing of a developing solution for the substratecooled in the cooling section.

Specifically, the apparatus comprises: a cassette station including amounting section on which a substrate cassette housing a plurality ofsubstrates is mounted and a delivery means for receiving and sending thesubstrate from/to the substrate cassette mounted on the mountingsection; a processing station, connected to the cassette station, forprocessing the substrate transferred by the delivery means; an alignerprovided on the opposite side to the cassette station of the processingstation; and an interface station, connected to the opposite side to thecassette station of the processing station, for delivering the substratebetween the processing station and the aligner, and the interfacestation includes a reaction inhibiting section for performing processingof inhibiting the progress of a resolution reaction of a resist for asubstrate coated with the resist and exposed, and the processing stationincludes a heating section for heating the substrate processed in thereaction inhibiting section to progress the resolution reaction of theresist, a cooling section for cooling the substrate heated in theheating section to inhibit the progress of the resolution reaction ofthe resist, and a developing processing section for performing coatingprocessing of a developing solution for the substrate.

In such a substrate processing apparatus, the progress of the resolutionreaction of the resist is inhibited during the transfer of the substratefrom the aligner to the heating section, and thus in the heatingsection, the resolution reaction progresses on the same condition forthe substrate in which the extent of the progress of the resolutionreaction is made uniform. Therefore, when developing processing isperformed, the extent of the progress of the resolution reaction is madeuniform over the entire substrate, whereby the occurrence of theununiformity of developing line width is suppressed.

In the above, it is desirable to place the reaction inhibiting sectionnear the aligner, in which case the time of transfer between the alignerand the reaction inhibiting section is shortened, whereby the extent ofthe progress of the resolution reaction of the substrate transferred tothe reaction inhibiting section is made more uniform, resulting in arise in the uniformity of developing line width.

In this case, it is desirable that the reaction inhibiting section havea structure characterized by inhibiting the progress of the resolutionreaction of the resist by cooling the substrate coated with the resistand exposed so as not to cause dew formation. Also, it is desirable thatit have a structure characterized by inhibiting the progress of theresolution reaction of the resist by making the amount of moistureadhering to the substrate coated with the resist and exposed smallerthan the amount of moisture adhering to the substrate when the substrateis transferred to the reaction inhibiting section, and characterized,for example, by making the amount of the moisture adhering to thesubstrate smaller than the amount of the moisture adhering to thesubstrate when the substrate is transferred to the reaction inhibitingsection by supplying a gas having a humidity lower than the humidity ofair in an atmosphere in which the reaction inhibiting section is placed.

The resist is a chemically amplified resist, the resolution reaction ofwhich is progressed by an acid produced by exposure, for example, inwhich case the resolution reaction of the resist is a reaction that anacid produced by exposure decomposes a basic resin which is a maincomponent of a resist material or changes its molecular structure tomake the basic resin soluble in a developing solution.

Therefore, in a substrate processing method of the present inventioncomprising the steps of: heating a substrate coated with a resist andexposed in a heating section to progress a resolution reaction of theresist; cooling the substrate to inhibit the progress of the resolutionreaction of the resist; and performing coating processing of adeveloping solution for the substrate, the exposed substrate istransferred to the heating section with the resolution reaction of theresist being inhibited.

Such a method is carried out by a substrate processing apparatuscharacterized by comprising: an exposure section for exposing asubstrate coated with a resist; a heating section for heating theexposed substrate to progress a resolution reaction of the resist; acooling section for cooling the heated substrate to inhibit the progressof the resolution reaction of the resist; and a developing processingsection for performing coating processing of a developing solution forthe cooled substrate, and transferring the exposed substrate to theheating section by a substrate transfer means with the resolutionreaction of the resist being inhibited.

In this case, for example, the exposed substrate is transferred to theheating section with the progress of the resolution reaction of theresist being inhibited by being cooled so as not to cause dew formation.Moreover, the substrate may be transferred to the heating section withthe progress of the resolution reaction of the resist being inhibited bymaking the amount of moisture adhering to the substrate when thesubstrate is transferred to the heating section smaller than the amountof moisture adhering to the substrate after exposure, in which case theexposed substrate is transferred to the heating section while a gashaving a humidity lower than air is being supplied to the substrate.

Specifically, the apparatus has a structure characterized by comprising:a cassette station including a mounting section on which a substratecassette housing a plurality of substrates is mounted and a deliverymeans for receiving and sending the substrate from/to the substratecassette mounted on the mounting section; a processing station,connected to the cassette station, for processing the substratetransferred by the delivery means; an aligner provided on the oppositeside to the cassette station of the processing station; an interfacestation, connected to the opposite side to the cassette station of theprocessing station, for delivering the substrate between the processingstation and the aligner, and characterized in that the interface stationcomprises a heating section for heating the exposed substrate toprogress a resolution reaction of a resist, the processing stationcomprises: a cooling section for cooling the substrate heated in theheating section to inhibit the progress of the resolution reaction ofthe resist; and a developing processing section for performing coatingprocessing of a developing solution for the substrate, and that theinterface station is cooled so as not to cause dew formation on thesubstrate to inhibit the progress of the resolution reaction of theresist.

In such a invention, the progress of the resolution reaction of theresist is inhibited during the transfer of the substrate from thealigner to the heating section, and thus in the heating section, theresolution reaction progresses on the same condition for the substratein which the extent of the progress of the resolution reaction is madeuniform. Therefore, when developing processing is performed, the extentof the progress of the resolution reaction is made uniform over theentire substrate, whereby the occurrence of the ununiformity of thedeveloping line width is suppressed.

Moreover, the resist is a chemically amplified resist, the resolutionreaction of which is progressed by an acid produced by exposure, forexample, in which case the resolution reaction of the resist is areaction that an acid produced by exposure decomposes a basic resinwhich is a main component of a resist material or changes molecularstructure to make the basic resin soluble in a developing solution.

These objects and still other objects and advantages of the presentinvention will become apparent upon reading the following specificationwhen taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing the external appearance of a coating anddeveloping processing system according to a first embodiment of thepresent invention;

FIG. 2 is a front view of the coating and developing processing systemin FIG. 1;

FIG. 3 is a rear view of the coating and developing processing system inFIG. 1;

FIG. 4 is a horizontal sectional view showing an outline of aheating/cooling processing unit in the coating and developing processingsystem in FIG. 1;

FIG. 5 is an explanatory view showing the flow of an inert gas suppliedto the coating and developing processing system in FIG. 1;

FIG. 6 is an explanatory view showing the flow of the inert gas when anatmosphere inside the coating and developing processing system is reusedas the inert gas;

FIG. 7 is a plan view showing the external appearance of a coating anddeveloping processing system according to a second embodiment of thepresent invention;

FIG. 8 is a front view of the coating and developing processing systemin FIG. 7;

FIG. 9 is an explanatory view of a vertical section of a processingstation;

FIG. 10 is an explanatory view of a vertical section of an interfacesection;

FIG. 11 is a horizontal sectional view showing an outline of aheating/cooling processing unit in the coating and developing processingsystem in FIG. 7;

FIG. 12 is an explanatory view of a case in which the flow of an inertgas supplied to the interface section is seen from the side of thecoating and developing processing system;

FIG. 13 is an explanatory view of a vertical section showing the flow ofthe inert gas supplied to the interface section;

FIG. 14 is an explanatory view showing the state of a resist film inwhich a circuit pattern is exposed;

FIG. 15 is an explanatory view showing the state of the resist filmafter developing;

FIG. 16 is a plan view of a substrate processing apparatus according toa third embodiment of the present invention;

FIG. 17 is a schematic plan view showing a coating and developing systemaccording to a fourth embodiment of the present invention;

FIG. 18 is a schematic perspective view showing the coating anddeveloping system;

FIG. 19 is a side view showing an example of a shelf unit and adeveloping unit of the coating and developing system;

FIG. 20 is a side view showing an example of the shelf unit of thecoating and developing system;

FIG. 21A to FIG. 21D are sectional views each showing a CHP processstation provided in the shelf unit;

FIG. 22 is a sectional view showing an example of the developing unit;

FIG. 23 is a sectional view showing a substrate transfer means;

FIG. 24 is a sectional view showing an example of a reaction inhibitingsection;

FIG. 25 is a perspective view showing an example of an interfacestation;

FIG. 26A to FIG. 26C are explanatory views showing a resolution reactionof a chemically amplified resist;

FIG. 27 is a sectional view showing another example of the reactioninhibiting section;

FIG. 28 is a schematic plan view showing a conventional coating anddeveloping system;

FIG. 29 is a view for explaining an applied example of the fourthembodiment;

FIG. 30 is a view for explaining an applied example of the fourthembodiment;

FIG. 31 is a schematic plan view showing a coating and developing systemaccording to a fifth embodiment of the present invention;

FIG. 32 is a schematic perspective view showing the coating anddeveloping system;

FIG. 33 is a side view showing an example of a shelf unit and adeveloping unit of the coating and developing system;

FIG. 34 is a side view showing an example of the shelf unit of thecoating and developing system;

FIG. 35 is a sectional view showing an example of the developing unit;

FIG. 36A to FIG. 36D are sectional views each showing a CHP processstation provided in the shelf unit;

FIG. 37 is a perspective view showing an example of an interfacestation;

FIG. 38 is a sectional view showing an example of the interface station;

FIG. 39 is a side view showing an example of the CHP process station anda partition wall;

FIG. 40A to FIG. 40C are explanatory views showing a resolution reactionof a chemically amplified resist;

FIG. 41 is a sectional view showing another example of the coating anddeveloping system;

FIG. 42 is a sectional view showing another example of the shelf unit inwhich the CHP process station is provided;

FIG. 43 is a sectional view showing still another example of the coatingand developing system;

FIG. 44 is an exploded perspective view showing yet another example ofthe coating and developing system;

FIG. 45 is an explanatory view of a sixth embodiment of the presentinvention; and

FIG. 46 is an explanatory view of another example of the sixthembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, the preferred embodiments of the present invention will beexplained.

First Embodiment

FIG. 1 is a plane view of a coating and developing processing system(substrate processing apparatus) 1 according to this embodiment, FIG. 2is a front view of the coating and developing processing system 1, andFIG. 3 is a rear view of the coating and developing processing system 1.

The coating and developing processing system 1, as shown in FIG. 1, hasa structure in which a cassette station 2 as a loader/unloader section,for carrying, for example, 25 wafers W in a cassette into/out of thecoating and developing processing system 1 from/to the outside and forcarrying the wafer W into/out of a cassette C, a processing station 3 asa processing section, in which various processing units for performingpredetermined processing for wafers W one by one in a process of acoating and developing processing are disposed in multiple tiers, and aninterface section 4 which receives and sends the wafer W from/to analigner 5 provided next to the coating and developing processing system1 are integrally connected in its casing 1 a.

In the cassette station 2, a plurality of cassettes C are freely mountedin an X-direction (in a top and bottom direction in FIG. 1) in a line atpredetermined positions on a cassette mounting table 6 as a mountingsection. Further, a wafer carrier 7 which can be transported in thedirection of arrangement of the cassettes (the X-direction) and thedirection of arrangement of the wafers W housed in the cassette C (az-direction; a vertical direction) is provided to be movable along atransfer path 8, and can selectively get access to the respectivecassettes C.

The wafer carrier 7 has an alignment function of aligning the wafer W.This wafer carrier 7 is also structured to be able to get access to anextension unit 32 and an adhesion unit 31 which belong to a thirdprocessing unit group G3 of the processing station 3, as will bedescribed later. Between the cassette station 2 and the processingstation 3, a partition plate 10 for shutting off an atmosphere in thecassette station 2 from an atmosphere in the processing station 3 isprovided. Further, a transit opening 11 is provided in the partitionplate 10 at a position opposite to the aforesaid extension unit 32 andadhesion unit 31 which belong to the third processing unit group G3 sothat the wafer W can be transferred between the cassette station 2 andthe processing station 3 by the wafer carrier 7. Furthermore, a shutter12 for freely opening/closing the transit opening 11 is provided in thetransit opening 11, and the shatter 12 is opened only when the wafer Wpasses through the transit opening 11 and closed at all other times.

In the processing unit 3, a main transfer device 13 as a first transferdevice is provided in its center portion, and around the main transferdevice 13, various processing units are disposed in multiple tiers tocompose processing unit groups. In this coating and developingprocessing system 1, four processing unit groups G1, G2, G3, and G4 aredisposed, in which a first and second processing unit groups G1 and G2are disposed on the front side of the coating and developing processingsystem 1, the third processing unit group G3 is disposed next to thecassette station 2, and a fourth processing unit group G4 is disposednext to the interface section 4. Further, a fifth processing unit groupG5 shown by a broken line can be optionally disposed as an extra on therear side. The main transfer device 13 can carry the wafer W into/out ofvarious processing units which are disposed in the processing unitgroups G1, G2, G3, and G4.

In the first processing unit group G1, for example as shown in FIG. 2, aresist coating unit 17 for coating the wafer W with a resist solutionand a developing processing unit 18 for performing a developingprocessing for the wafer W after exposure processing are two-tiered fromthe bottom in order. Similarly in the second processing unit group G2, aresist coating unit 19 and a developing processing unit 20 aretwo-tiered from the bottom in order. Incidentally, in the resist coatingunit 17 or 19 and the developing processing unit 18 or 20, an atmospherecontroller not illustrated for maintaining a predetermined atmosphere ineach unit is provided to maintain a clean atmosphere in each unit and tomaintain a pressure inside each unit at a predetermined pressure.

In the third processing unit group G3, for example as shown in FIG. 3, acooling unit 30 for cooling the wafer W, the adhesion unit 31 forenhancing adhesion properties of the resist solution and the wafer W,the extension unit 32 for making the wafer W wait, cooling units 33 and34 for cooling the wafer W after the developing processing, post-bakingunits 35 and 36 for performing heating processing for the wafer W afterthe developing processing, and the like are, for example, seven-tieredfrom the bottom in order.

In the fourth processing unit group G4, for example, a cooling unit 40,extension units 41 and 42 for mounting the wafer W before and after theexposure processing and temporarily making the wafer W wait,heating/cooling processing units 43, 44, and 45 for heating the wafer Wafter the exposure processing and thereafter cooling it to apredetermined temperature (PEB/COL in FIG. 3), heating/coolingprocessing units 46 and 47 for heating the wafer W in order to vaporizea solvent in the resist solution and thereafter cooling it to apredetermined temperature (PRE/COL in FIG. 3) and the like are, forexample, eight-tiered from the bottom in order.

The aforesaid heating/cooling processing unit 43 includes, as shown inFIG. 4, a disc-shaped hot plate 51 for heating the wafer W and a chillplate 52 which moves to a position above the hot plate 51 and receivesthe wafer W from above the hot plate 51 to cool it on a base table 50inside its casing 43 a. The wafer W continuously undergoes theheating/cooling processing in the same unit, to thereby keep a thermalbudget which is given to the wafer W by heating constant. Incidentally,the structures of the other heating/cooling processing units 44 to 47are the same as the heating/cooling processing unit 43.

A wafer carrier 55 as a second transfer device is provided in the centerportion of the interface section 4. This wafer carrier 55 is structuredto be movable in the X-direction (in the top and bottom direction inFIG. 1) and the Z-direction (the vertical direction), and to berotatable in a θ-direction (a rotating direction around a Z-axis), andto be able to get access to the extension units 41, 42 which belong tothe fourth processing unit group G4, a peripheral exposure unit 56 andthe aligner 5, and to carry the wafer W to each of them.

Between the interface section 4 and the processing station 3, apartition plate 60 for shutting off an atmosphere inside the interfacesection 4 from an atmosphere inside the processing station 3 isprovided. Further, a transit opening 61 is provided in the partitionplate 60 at a position opposite to the extension units 41 and 42 whichbelong to the fourth processing unit group G4 so that the wafer W can betransferred between the processing station 3 and the interface section 4by the aforesaid wafer carrier 55. Furthermore, a shutter 62 for freelyopening and closing the transit opening 61 is provided in the transitopening 61, and the shatter 62 is opened only when the wafer W passesthrough the transit opening 61 and closed at all other times.

The aligner 5 for subjecting the wafer to the exposure processing isprovided next to the interface section 4. The aligner 5 is sealed by acasing 5 a of the aligner 5 and structured to be able to strictlycontrol an atmosphere inside the aligner 5. Further, a transit opening65 for carrying the wafer W into/out of the interface section 4 isprovided on the interface section 4 side of the casing 5 a, and ashutter 66 for freely opening and closing the transit opening 65 isprovided in the transit opening 65.

On top of the aforesaid respective areas of the coating and developingprocessing system 1, that is, on top of the cassette station 2, theprocessing station 3, and the interface section 4, gas supply devices70, 71, and 72 for supplying an inert gas are respectively provided asshown in FIG. 5, and it is possible to supply the inert gas individuallyfrom the gas supply device 70 into the cassette station 2, from the gassupply device 71 into the processing station 3, and from the gas supplydevice 72 into the interface section 4.

Filter devices 70 a, 71 a, and 72 a are respectively provided in the gassupply devices 70, 71, and 72, and each of the filter devices 70 a, 71a, and 72 a includes a temperature/humidity regulating means forregulating the inert gas supplied from a supply source not illustratedor the like at a predetermined temperature and a predetermied humidity,a ULPA filter for removing fine particles in the inert gas, and achemical filter for neutralizing alkaline components contained in theinert gas. Therefore, the inert gas which is cleaned and the temperatureand humidity of which are regulated by each area can be supplied to therespective areas in the coating and developing processing system 1, thatis, the cassette station 2, the processing station 3, and the interfacesection 4.

Meanwhile, at the bottom of the respective areas of the cassette station2, the processing station 3, and the interface section 4, exhaust pipes75, 76, and 77 as exhaust means are respectively provided, and theexhaust pipes 75, 76, and 77 are connected to a plant exhaust pipe 78and are structured so that the atmosphere in each area is exhausted tothe outside of the coating and developing processing system 1.Therefore, the inert gas supplied from the gas supply devices 70, 71,and 72 into the respective areas passes each area to be exhausted fromthe exhaust pipes 75, 76, and 77, and impurities such as oxygen, ozone,vapor, and so on in the respective areas are purged to keep theatmosphere clean in the respective areas. Further, the pressure in eacharea is controlled at a predetermined pressure by regulating the supplyamount of the inert gas from the gas supply devices 70, 71, and 72 whichcorrespond to the respective areas.

Next, a process of a photolithography which is operated in the coatingand developing processing system 1 thus structured will be explained.

Before starting the processing of the wafer W, the inert gas which isregulated at predetermined temperature and humidity, for example, at 23°C. and 45%, and is rid of fine particles is supplied to each area in thecoating and developing processing system 1, that is, the cassettestation 2, the processing station 3, and the interface section 4 by thegas supply devices 70, 71, and 72. Then, the atmosphere in each area isreplaced with a clean atmosphere not containing impurities such as fineparticles and oxygen, and this state is maintained thereafter. Further,a pressure P1 in the cassette station 2, a pressure P2 in the processingstation 3, a pressure P3 in the interface section 4, and a pressure P4in the aligner 5 are set so that these have a relationship of P4>P3,P3>P2, P2>P1, thereby preventing the atmosphere inside the interfacesection 4 from flowing into the aligner 5, and the atmosphere inside thecassette station 2 and the interface section 4 from flowing into theprocessing station 3.

Moreover, as shown in FIG. 1, the pressure P2 in the processing station3 is set to be lower than a pressure P5 in the resist coating units 17and 19 and the developing processing units 18 and 20 which independentlycontrol the atmosphere therein as described above, thereby preventingthe atmosphere in the processing station 3 from flowing into the unitsuch as the resist coating unit 17 and the like. Further, the pressuresP1 to P5 are set to be higher than a pressure P0 inside a clean room inwhich the coating and developing processing system 1 is installed, sothat the direct flow of an atmosphere inside the clean room whichcontains impurities, fine particles, and so on into the coating anddeveloping processing system 1 is prevented.

Then, the processing of the wafer W is started, and in the cassettestation 2 in which the atmosphere is kept clean, the wafer carrier 7first removes one unprocessed wafer W from the cassette C and carries itthrough the transit opening 11 into the adhesion unit 31 of theprocessing station 3 in which the atmosphere is kept clean. At thistime, the shutter 12 is temporarily opened, and when the wafer W iscarried into the adhesion unit 31, the shutter 12 is closed again.

Then, the wafer W, coated with an adhesion reinforcing agent such asHMDS for enhancing an adhesion property with the resist solution in theadhesion unit 31, is carried into the cooling unit 30 by the maintransfer device 13 to be cooled to a predetermined temperature.Thereafter, the wafer W is carried into the resist coating unit 17 or 19to undergo resist coating processing. Then, the wafer W on which theresist film is formed is transferred to the heating/cooling processingunit 46 or 47 (PRE/COL in FIG. 3) to undergo heating/cooling processing.On this occasion, heating processing and cooling processing are notperformed successively in the respective units provided individually,but the heating processing and the cooling processing are performed inthe single unit such as the heating/cooling processing unit 46 or 47, sothat the time required from the heating processing to the coolingprocessing for the wafer W can be kept constant at all times, whichmakes it possible to make the thermal budget which is given to the waferW by the heating the same between the respective wafers W. Further, inthis embodiment, all the heating/cooling processing from the resistcoating processing to the developing processing is performed by usingthe heating/cooling processing units 43 to 47, whereby the time requiredfrom the resist coating to the developing processing can be made thesame in all of the wafers W.

Subsequently, when the wafer W is carried into the extension unit 41 andthe shutter 62 is opened, the wafer carrier 55 receives the wafer W fromthe extension unit 41 to carry it into the peripheral exposure unit 56in the interface section 4 in which the atmosphere is kept clean. Theshutter 62 is closed again when the carrying in/out of the wafer W iscompleted. After a peripheral portion of the wafer W is exposed in theperipheral exposure unit 56, the wafer W is carried into the aligner 5through the transit opening 65. Here, after the shutter 66 is opened andthe wafer W is carried into the aligner 5, the shutter 66 is closedagain.

Next, the wafer W which has undergone exposure by being exposedaccording to a predetermined pattern in the aligner 5 passes through theinterface section 4 to be carried into the extension unit 42 in theprocessing station 3 again by the wafer carrier 55. Then, the wafer W iscarried into the heating/cooling processing unit 43, 44 or 45 by themain transfer device 13 to undergo heating/cooling processing after theexposure processing in due order.

Thereafter, the wafer W is transferred to the developing processing unit18 or 20 to undergo developing processing. The wafer W after thedeveloping processing is carried into the post-baking unit 35 or 36 tobe heated, and subsequently, transferred to the cooling unit 33 or 34 tobe cooled to a predetermined temperature. Then, it is carried into theextension unit 32 of the third processing unit group and returned to thecassette C in the cassette station 2 by the wafer carrier 7. The aboveprocess completes a successive photolithography process.

According to this embodiment described above, since the inert gas issupplied to each area of the cassette station 2, the processing station3, and the interface section 4, the impurities such as oxygen and thefine particles in each area are reduced and removed, whereby theatmosphere in each area can be maintained clean. Therefore, the adhesionof the impurities such as oxygen and the fine particles to the wafer Wduring the processing is suppressed, so that the transfer of the wafer Wand each processing can be preferably performed in the coating anddeveloping processing system 1. Especially in the aligner 5, aninfluence due to the impurities such as oxygen is significant, and theremoval of the impurities such as oxygen inside the interface section 4can suppress the adhesion of the impurities to the wafer which isimmediately before being carried into the aligner 5, which contributesto the yield of the wafer W to a great extent. Further, as a wavelengthof a laser beam used in the aligner 5 is shorter, the influence due tothe impurities becomes more significant, and hence the laser beam with ashorter wavelength, for example, 157 nm is more effectively used.

Moreover, the pressure P4 in the aligner 5 is set to be higher than thepressure P3 in the interface section 4, and the pressure P3 in theinterface section 4 and the pressure P1 in the cassette station 2 areset to be lower than the pressure P2 in the processing station 3,thereby suppressing the flow of the atmosphere in the interface section4 into the aligner 5, and the flows of the atmospheres in the interfacesection 4 and the cassette station 2 into the processing station 3.Therefore, predetermined atmospheres are maintained in the aligner 5 andthe processing station 3.

Further, the pressure P2 in the processing station 3 is set to be lowerthan the pressure P5 in the resist coating units 17 and 19 and thedeveloping processing units 18 and 20 in the processing station 3,thereby preventing the inert gas in the processing station 3 fromflowing into the resist coating unit 17 and the like, which makes itpossible to perform the resist coating processing and the developingprocessing for the wafer W in the predetermined atmosphere.

Furthermore, the pressures P1 to P5 in the respective areas are set tobe higher than the pressure P0 in the clean room and therefore, it isprevented that the atmosphere in the clean room which includesimpurities and fine particles in comparatively large quantities directlyflows into the coating and developing processing system 1 to contaminatethe interior of the coating and developing processing system 1.

Moreover, the partition plate 10 is provided between the cassettestation 2 and the processing station 3, the partition plate 60 isprovided between the processing station 3 and the interface section 4,and the shutters 12 and 62 are respectively provided in the partitionplates 10 and 60, whereby the mutual interference of atmospheres in therespective areas is further suppressed, and the wafer W can be processedin the predetermined atmosphere by each area.

The aforesaid inert gas is supplied to each area after the temperatureand the humidity thereof are regulated at predetermined temperature andhumidity, whereby the temperature and the humidity in each area aremaintained at the predetermined temperature and humidity, and the waferW can be processed in the same condition at all times.

According to this embodiment described above, the atmosphere in eacharea exhausted from each of the exhaust pipes 75, 76, and 77 isexhausted as it is to the outside of the coating and developingprocessing system 1, but this atmosphere can be used again as the inertgas supplied from the gas supply devices 70, 71, and 72. In such a case,for example as shown in FIG. 6, a main exhaust pipe 90 which leads tothe respective exhaust pipes 75, 76, and 77 is provided, and this mainexhaust pipe 90 is made to lead to the aforesaid gas supply devices 70,71 and 72. Further, in the main exhaust pipe 90, a filter 91 such as anozone filter, a silica gel filter, a deoxidant filter, or the like and afan 92 are provided. Based on the above structure, the atmosphere whichis exhausted from each area is cleaned and supplied to the respectivegas supply devices 70, 71, and 72 to be reused as the inert gas. Thefilter 91 has a function of removing impurities such as oxygen, and canremove the impurities in the atmosphere which run through the respectiveareas. Incidentally, instead of the filter 91, a device which can removeoxygen, ozone, moisture, and so on may be provided to clean theaforesaid atmosphere.

Thus, by reusing the atmosphere exhausted from each of the exhaust pipes75, 76, 77 as the inert gas, the amount of the inert gas to be newlysupplied and energy required for regulating the temperature can bereduced.

In the embodiment described above, the inert gas is supplied to all ofthe areas of the cassette station 2, the processing station 3, and theinterface section 4, but it can be supplied only to the interfacesection 4. The aforesaid supply of the inert gas to the interfacesection 4 and removal of the impurities from the interface section 4 cansuppress the adhesion of the impurities to the wafer W immediatelybefore and after the exposure processing in which the impurities exertthe most significant influence thereon.

Further, the inert gas may be supplied only to the interface section 4and the processing station 3. Thus, by supplying the inert gas to theprocessing station 3 in addition to the interface section 4 as describedabove, a clean atmosphere is maintained in the processing station 3 inwhich the majority of processing of the coating and developingprocessing is performed, and the wafer W can be processed in the cleanatmosphere.

Incidentally, the above explained embodiment is about the coating anddeveloping processing system of the wafer W in the process ofphotolithography in a fabricating process of a semiconductor waferdevice, but the present invention is also applicable to a coating anddeveloping processing system of substrates other than a semiconductorwafer, such as an LCD substrate.

According to the present invention, the inert gas is supplied into thecoating and developing processing system to suppress the adhesion ofimpurities at molecular level such as oxygen, ozone, organic substances,and the like to the substrate, whereby the substrate is suitablyprocessed without being influenced by the impurities, which makes itpossible to enhance yield.

In particular, by removing the impurities in the interface section, thesubstrate which is not contaminated by the impurities is carried intothe aligner, and the exposure processing of the substrate can besuitably operated.

Second Embodiment

FIG. 7 is a plane view of a coating and developing processing system 101according to the second embodiment, and FIG. 8 is a front view of thecoating and developing processing system 101.

The coating and developing processing system 101, as shown in FIG. 7,has a structure in which a cassette station 102 for carrying, forexample, 25 wafers W in a cassette into/out of the coating anddeveloping processing system 101 from/to the outside and carrying thewafer W into/out of a cassette C, a processing station 103 as aprocessing section, in which various processing units are disposed inmultiple tiers for performing predetermined processing for the wafers Wone by one in a process of the coating and developing processing, and aninterface section 104 for receiveing and sending the wafer W from/to analigner 105 provided next to the coating and developing processingsystem 101 are integrally connected in its casing 101 a.

In the cassette station 102, a plurality of cassettes C are freelymounted in the X-direction (in a top and bottom direction in FIG. 7) ina line at predetermined positions on a cassette mounting table 106 as amounting section. Further, a wafer carrier 107 which can be transportedin the direction of arrangement of the cassettes (the X-direction) andthe direction of arrangement of wafers W housed in the cassette C (theZ-direction; a vertical direction) is provided to be movable along atransfer path 108, and can get access selectively to the respectivecassettes C.

The wafer carrier 107 has an alignment function of performing alignmentof the wafer W. This wafer carrier 107 is also structured to be able toget access to an extension unit 132 and an adhesion unit 131 whichbelong to a third processing unit group G3 of the processing station103, as will be described later.

In the processing station 103, a main transfer device 113 as a substratetransfer device is provided on the interface section 104 side, and onthe cassette station 102 side, three processing unit groups G1, G2, andG3 are disposed. In each of the processing unit groups G1, G2, and G3,various processing units are disposed in multiple tiers. A firstprocessing unit group G1 is disposed on the front side of the coatingand developing processing system 101, and a second processing unit groupG2 is disposed on the rear side of the coating and developing processingsystem 101, with a third processing unit group G3 therebetween. The maintransfer device 113 can carry the wafer W into/out of various processingunits which are disposed in the processing unit groups G1, G2, and G3and will be described later, and can also carry the wafer W into/out ofprocessing unit groups G4, G5 which are disposed in the interfacesection and will be described later.

In the first processing unit group G1, for example as shown in FIG. 8and FIG. 9, resist coating units 117 and 118 for coating the wafer Wwith a resist solution are two-tiered from the bottom in order. In thesecond processing unit group G2, developing processing units 119 and 120for performing developing processing for the wafer W after exposureprocessing are two-tiered from the bottom in order. In the thirdprocessing unit group G3, a cooling unit 130 for performing a coolingprocessing for the wafer W, the adhesion unit 131 for enhancing adhesionproperties of the resist solution and the wafer W, the extension unit132 for making the wafer W wait, cooling units 133 and 134 for coolingthe wafer W after the developing processing, post-baking units 135 and136 for performing heating processing for the wafer W after thedeveloping processing and the like are, for example, seven-tiered fromthe bottom in order.

The interface section 104 includes an area S1 before exposure in whichthe fourth processing unit group G4 having a first thermal processingunit and a first wafer carrier 140 as a first transfer device aredisposed, and an area S2 after exposure in which the fifth processingunit group G5 having a second thermal processing unit and a second wafercarrier 141 as a second transfer device are disposed. Further, anatmosphere in the area S1 before exposure and an atmosphere in the areaS2 after exposure are shut off by a partition plate 142 so that theatmospheres in the area S1 before exposure and the area S2 afterexposure are made to be different from each other.

In the fourth processing unit group G4, for example, a cooling unit 150,extension units 151 and 152 for mounting the wafer W before exposureprocessing and temporarily making it wait, heating/cooling processingunits 153, 154, 155, and 156 (PREBAKE/COL in FIG. 9) for heating thewafer W before exposure processing in order to vaporize a solvent in theresist solution and thereafter cooling it to a predeterminedtemperature, and the like are, for example, seven-tiered from the bottomin order.

The aforesaid heating/cooling processing unit 153 includes, as shown inFIG. 11, a disc-shaped hot plate 158 for heating the wafer W and a chillplate 159 which moves to a position above the hot plate 158 and receivesthe wafer W from above the hot plate 158 to cool it on a base table 153b inside its casing 153 a. The wafer W undergoes heating/coolingprocessing in the same unit continuously, to thereby keep a thermalbudget which is given to the wafer W by the heating constant.Incidentally, the structures of the other heating/cooling processingunits 154 to 156 are the same.

The first wafer carrier 140 is structured to be movable in the X- andthe Y-direction (in the top and bottom direction and a right and leftdirection in FIG. 7) and the Z-direction (the vertical direction), andto be rotatable in the θ-direction (a rotating direction around aZ-axis), and to be able to get access to the various processing unitswhich belong to the fourth processing unit group G4, a peripheralexposure unit 157 and the aligner 105, and to carry the wafer W to eachof them.

In the fifth processing unit group G5, for example, a cooling unit 160,extension units 161 and 162 for mounting the wafer W after exposureprocessing and temporarily making it wait, heating/cooling processingunits 163, 164, 165, and 166 (PEB/COL in FIG. 3) for heating the wafer Wafter the exposure processing and thereafter cooling it to apredetermined temperature, and the like are, for example, seven-tieredfrom the bottom in order.

The heating/cooling processing units 163 to 166 have the same structureswith that of the aforesaid heating/cooling processing unit 153. Thesecond wafer carrier 141 is structured similarly to the aforesaid firstwafer carrier 140, which is structured to be able to get access to thevarious processing units which belong to the fifth processing unit groupG5 and the aligner 105, and to carry the wafer W to each of them.

Between the processing station 103 and the interface section 104, apartition plate 170 is provided. By this partition plate 170, anatmosphere of the processing station 103 and an atmosphere of theinterface section 104 are shut off from each other. Further, a firsttransit opening 171 is provided in the partition plate 170 at a positionopposite to the extension units 151 and 152 which belong to the fourthprocessing unit group G4 so that the main transfer device 113 getsaccess to the extension units 151 and 152 to carry the wafer W into thearea S1 before exposure from the processing station 103. Furthermore, afirst shutter 172 for freely opening and closing the first transitopening 171 is provided in the first transit opening 171, and the firstshatter 172 is opened only when the wafer W passes through the firsttransit opening 171 and closed at all other times.

A second transit opening 173 is provided in the partition plate 170 at aposition opposite to the extension units 161 and 162 which belong to thefifth processing unit group G5 so that the main transfer device 113 getsaccess to the extension units 161 and 162 to carry the wafer W into theprocessing station 103 from the area S2 after exposure. Furthermore, asecond shutter 174 for freely opening and closing the second transitopening 173 is provided in the second transit opening 173, and thesecond shatter 174 is opened only when the wafer W passes through thesecond transit opening 173 and closed at all other times.

The aligner 105 for subjecting the wafer W to exposure processing isprovided next to the interface section 104. The aligner 105 is sealed bya casing 105 a of the aligner 105, and is structured to be able tostrictly control an atmosphere in the aligner 105. Further, a transitopening 175 for carrying the wafer W from the interface section 104 intothe aligner 105 is provided on the area S1 before exposure side of theinterface section 104 of the casing 105 a, and a shutter 176 for freelyopening and closing the transit opening 175 is provided in the transitopening 175. Furthermore, a transit opening 177 for carrying the wafer Wfrom the aligner 105 into the interface section 104 is provided on thearea S2 after exposure side of the interface section 104 of the casing105 a, and a shutter 178 for freely opening and closing the transitopening 177 is provided in the transit opening 177.

A first gas supply device 180 and a second gas supply device 181 arerespectively provided above the area S1 before exposure of the interfacesection 104 and above the area S2 after the exposure thereof, so thatthe inert gas can be individually supplied from the first gas supplydevice 180 to the area S1 before exposure and from the second gas supplydevice 181 to the area S2 after exposure.

The gas supply devices 180 and 181 each include a function of regulatingthe inert gas supplied from a supply source not illustrated or the liketo predetermined temperature and humidity, and ULPA filters 180 a and181 a for removing fine particles in the inert gas, so that the inertgas which is cleaned and the temperature and humidity of which areregulated by each area can be supplied to the area S1 before exposureand the area S2 after exposure of the interface section 104.Particularly, the second gas supply device 181 is set to supply theinert gas with a temperature lower than the temperature of the inert gassupplied from the gas supply device 180 before exposure, and hence thereis a temperature difference between the atmospheres in the area S1before exposure and the area S2 after exposure.

A first exhaust pipe 182 and a second exhaust pipe 183 are respectivelyprovided underneath the area S1 before exposure and underneath the areaS2 after exposure, and each of them is structured to be able to exhaustthe atmosphere in each area. Therefore, the inert gas which is suppliedfrom the respective gas supply devices 180 and 181 into the respectiveareas passes each area to be exhausted from the respective exhaust pipes182 and 183, and impurities such as oxygen, basic substrates, vapor, andso on in the respective areas are removed to be able to keep theatmospheres in the respective areas clean. Further, the pressure in thearea S1 before exposure is controlled by regulating the supply amount ofthe inert gas from the first gas supply device 180, and the pressure inthe area S2 after exposure is controlled by regulating the supply amountof the inert gas from the second gas supply device 181 at predeterminedpressures, respectively.

Next, a process of photolithography which is performed in the coatingand developing processing system 101 structured above will be explained.

Before starting the processing of the wafer W, the inert gas which isregulated at predetermined temperature and humidity, for example, at 23°C. and 45% and is rid of fine particles is supplied into the area S1before exposure of the interface section 104 by the first gas supplydevice 180. Further, the inert gas which is regulated at, for example,15° C. and 50% and is rid of fine particles is supplied into the area S2after exposure of the interface section 104 by the second gas supplydevice 181. Then, an atmosphere in each area is replaced with a cleanatmosphere not containing impurities such as fine particles, oxygen,basic substrates and so on, and the temperature inside the area S2 afterexposure is made lower than that of the area S1 before exposure, andthis state is maintained thereafter. Here, a pressure P1 in the area S1before exposure, a pressure P2 in the area S2 after exposure, and apressure P3 in the aligner 105 are set so that these have a relationshipof P3>P1=P2, thereby preventing the atmosphere inside the interfacesection 104 from flowing into the aligner 105. Further, a pressure P0 ina clean room in which the coating and developing processing system 101is disposed is set to be lower than the pressure P1 in the area S1before exposure, the pressure P2 in the area S2 after exposure, thepressure P3 in the aligner 105, a pressure inside the cassette station102, and a pressure inside the processing station 103, therebypreventing the atmosphere in the clean room which contains impuritiesand fine particles from flowing into the coating and developingprocessing system 101 directly.

Then, the processing of the wafer W is started, and in the cassettestation 102, the wafer carrier 7 first removes one unprocessed wafer Wfrom the cassette C and carries it into the adhesion unit 131 of theprocessing station 103.

The wafer W, coated with an adhesion reinforcing agent such as HMDS forenhancing an adhesion property with the resist solution in the adhesionunit 131, is carried into the cooling unit 130 by the main transferdevice 113 to be cooled to a predetermined temperature. Thereafter, thewafer W is carried into the resist coating unit 117 or 118 to undergo aresist coating processing. Then, the wafer W on which the resist film isformed is carried into the extension unit 151 or 152 by the maintransfer device 113. At this time, the first shutter 172 is temporarilyopened to carry the wafer W into the extension unit 151 or 152, and thefirst shutter 172 is closed again.

In the area S1 before exposure in which the atmosphere is kept clean,the wafer W is carried from the extension unit 151 or 152 into theheating/cooling processing unit 153, 154, 155, or 156 (PREBAKE/COL inFIG. 10). In the heating/cooling processing unit 153, 154, 155, or 156,the heating and the cooling processing is performed. Here, heatingprocessing and cooling processing are not performed in the respectiveunits provided individually, but the heating processing and the coolingprocessing are performed in the single unit such as the heating/coolingprocessing unit 153 or the like so that the time required from theheating processing to the cooling processing for the wafer W can be keptconstant at all times, which makes it possible to make the thermalbudget which is given to the wafer w by heating the same between therespective wafers W.

Subsequently, the wafer W is carried from the heating/cooling processingunit 153, 154, 155, or 156 into the peripheral exposure unit 157 by thefirst wafer carrier 140. After a peripheral portion of the wafer W isexposed in the peripheral exposure unit 157, the wafer W is transferredto the aligner 105 through the transit opening 175. On this occasion,the shutter 176 is opened and when the wafer W is carried into thealigner 105, the shutter 176 is closed again.

Next, in the aligner 105, a resist film on the wafer W is exposedaccording to a predetermined pattern. A chemically amplified resist isused for the resist film, and the chemically amplified resist contains abasic polymer which is insoluble in an alkaline developing solution usedin the following developing processing and an acid generator. As shownin FIG. 14, in an exposed portion of a resist film 100, an acid (H+) isgenerated to cause a catalytic reaction. The wafer W after the exposureis carried out of the aligner 105 through the transit opening 177 by thesecond wafer carrier 141. At this time, the shutter 178 is opened andwhen the wafer W is carried out of the aligner 105, the shutter 178 isclosed again.

In the area S2 after exposure in which the temperature is maintained lowand the atmosphere is maintained clean, the wafer W is carried into theheating/cooling processing unit 163, 164, 165 or 166 (PEB/COL in FIG.10) to undergo heating and cooling processing after the exposureprocessing in due order. In PEB which is heating after the exposureprocessing, the acid is thermally diffused to stimulate the catalyticreaction in the exposed portion and a protective group for protecting ahydroxyl group of the basic polymer is cleaved. Thereby, the exposedportion becomes soluble in the alkaline developing solution, and anunexposed portion remains insoluble in the alkaline developing solution.Here, a typical reaction model of the chemically amplified resist when,for example, its basic polymer is a polyvinyl phenol is shown as in thefollowing.

Subsequently, the wafer W is carried from the heating/cooling processingunit 163, 164, 165, or 166 into the extension unit 161 or 162 by thesecond wafer carrier 141. Thereafter, the wafer W is carried out of theextension unit 161 or 162 by the main transfer device 113. On thisoccasion, the second shutter 174 is opened and the wafer W is carriedout of the aligner 105, and then the second shutter 174 is closed again.

Thereafter, the wafer W is transferred to the developing processing unit119 or 120 to undergo developing processing and, as shown in FIG. 15,the exposed portion is removed to form a predetermined circuit pattern.The wafer W after the developing processing is transferred to thepost-baking unit 135 or 136 to be heated, and subsequently, transferredto the cooling unit 133 or 134 to be cooled to a predeterminedtemperature. Then, the wafer W is carried into the extension unit 132 ofthe third processing unit group and returned to the cassette C in thecassette station 102 by the wafer carrier 107. The above processcompletes a successive photolithography process.

According to the embodiment described above, the inert gas is suppliedto the area S1 before exposure by the first gas supply device 180, andthe atmosphere in the area S1 before exposure is exhausted by the firstexhaust means 182, whereby the impurities such as oxygen, vapor, and thelike in the area S1 before exposure are removed and the area S1 beforeexposure can be maintained in a clean condition. Therefore, from theheating processing (PREBAKE) immediately before the exposure processinguntil the exposure processing, the wafer W can be transferred in theclean atmosphere, thereby preventing the impurities from adheringthereto.

Especially, after the heating processing of the wafer W on which theresist film is formed, the impurities are likely to adhere onto thewafer W, and if the impurities adhere to the wafer W in the exposureprocessing, there arises the possibility that the exposure processing isnot preferably performed because the impurities absorb energy of a laserbeam or the like which is used in the exposure. However, by keeping thearea S1 before exposure of the interface section 104 through which thewafer W passes immediately before the exposure processing in a cleancondition as described above, the exposure processing of the wafer W canbe suitably performed, which contributes to the yield of the wafer W toa great extent. Further, as the wavelength of the laser beam used in thealigner 105 is shorter, an influence due to the impurities becomes moresignificant, and hence the laser beam with the shorter wavelength, forexample, 157 nm is more effectively used.

Moreover, the inert gas is supplied to the area S2 after exposure by thesecond gas supply device 181, and the atmosphere in the area S2 afterexposure is exhausted by the second exhaust pipe 183 so that theatmosphere in the area S2 after exposure can be maintained in a cleancondition, similarly to the area S1 before exposure.

Especially, when the chemically amplified resist for forming the circuitpattern by the catalytic reaction of the acid is used on the wafer W,the acid is deactivated if the impurities (such as basic substrates)adhere to the wafer W after exposure processing. However, by keeping thearea S2 after exposure of the interface section 104 through which thewafer W passes immediately after the exposure processing in a cleancondition as described above, the deactivation of the acid can beprevented and the following developing processing can be preferablyperformed.

Moreover, the inert gas is supplied to the respective areas by theindividual gas supply devices and the area S1 befor exposure and thearea S2 after exposure are shut off from each other by the partitionplate 142, so that the mutual interference of the atmospheres in therespective areas can be prevented, and atmospheres peculiar to therespective areas can be maintained in the area S1 before exposure andthe area S2 after exposure. Therefore, the atmospheres in the waferroute before exposure and the wafer route after exposure in theinterface section can be controlled individually.

Especially, the second gas supply device 181 supplies the inert gas thetemperature of which is lower than an ordinary temperature, and hencethe area S2 after exposure can be maintained in a low-temperaturecondition. When the aforesaid chemically amplified resist has such aproperty that the protective group thereof for protecting the hydroxylgroup of the basic polymer initiates an elimination reaction even at theordinary temperature, the elimination reaction of the protective groupprogresses on the wafer W during the transfer of the wafer W in the areaS2 after exposure when the temperature of the atmosphere in the area S2after exposure is higher than the ordinary temperature, but theelimination reaction of the protective group during the transfer of thewafer W can be inhibited by maintaining the area S2 after exposure in alow-temperature condition. For example, in heating processing afterexposure (PEB), it is possible that the catalytic reaction of the acidis accelerated abruptly to make the elimination reaction of theprotective group progress properly, whereby polarity changes in theexposed portion and the unexposed portion thereof can be completed.Therefore, the circuit pattern can be satisfactorily formed and thesubsequent developing processing can be suitably performed.

Both of the first gas supply device 180 and the second gas supply device181 have a function of regulating the temperature, and hence the area S1before exposure and the area S2 after exposure can be respectivelymaintained at predetermined temperatures.

The pressure P1 in the area S1 before exposure and the pressure P2 inthe area S2 after exposure are set to be lower than the pressure P3 inthe aligner 105, so that the atmospheres in the area S1 before exposureand in the area S2 after exposure can be prevented from flowing into thealigner 105 in which the atmosphere is strictly controlled.

It should be noted that an example of the embodiment according to thepresent invention has been explained, but the present invention is notlimited to the above example and can take various forms. It is suitableto provide the gas supply devices on top of the cassette station 102 andthe processing station 102 respectively, and to provide the exhaustpipes at the bottom thereof respectively so that the interiors of thecassette station 102 and the processing station 103 can be maintained inthe clean condition. Thereby, the entire coating and developingprocessing system 101 can be maintained in the clean condition and asuccessive photolithography process can be suitably performed.

Further, in order to save the supply amount of the inert gas, forexample, it is suitable that the inert gas exhausted from the respectiveareas is collected partially or entirely, subsequently cleaned, andreused as the inert gas by sending it to each of the gas supply devices180 and 181.

Incidentally, the embodiment explained above is about the coating anddeveloping processing system of the wafer W in the process ofphotolithography in a fabricating process of a semiconductor waferdevice, but the present invention is also applicable to a coating anddeveloping processing system of substrates other than the semiconductorwafer, such as an LCD substrate.

As described above, according to the present invention, the inert gas issupplied into the coating and developing processing system to preventthe impurities at molecular level such as oxygen, basic substrates,ozone, organic substances, and the like from adhering to the substrate,whereby the substrate is suitably processed without being influenced bythe impurities, which makes it possible to enhance yield. Further, theatmospheres in the substrate route before exposure and the substrateroute after exposure in the interface section can be controlledindividually.

Especially, when the chemically amplified resist is used, it is possibleto prevent the acid generated in the exposure from being deactivated bythe reaction with basic substances in the air. Further, the area afterexposure can be maintained at the low temperature so that theelimination reaction of the protective group during the transfer of thewafer W can be inhibited. Therefore, the following developing processingcan be suitably performed.

Moreover, according to the present invention, the clean atmospherespeculiar to the respective areas are maintained in the area beforeexposure and the area after exposure, and the respective areas can bemaintained at predetermined temperatures. Further, the atmospheres inthe area before exposure and the area after exposure can be preventedfrom flowing into the aligner in which the atmosphere is strictlycontrolled.

Third Embodiment

Next, the third embodiment of the present invention will be explained.

FIG. 16 is a plane view of a substrate processing apparatus according tothis embodiment.

An apparatus 200 in FIG. 16 includes an interface section 202 in which achamber 201 for temporarily holding the wafer W delivered from aprocessing station 3 and to be transferred to the aligner 5, in theinterface section 4 in the system as shown in FIG. 1, for example.

An atmosphere inside the chamber 201 is controlled by an atmospherecontroller 203.

For example, the atmosphere controller 203 reduces the pressure insidethe chamber 201. Incidentally, the atmosphere controller 203 may bestructured to supply an inert gas into the chamber 201 and to supply dryair into the chamber 201.

Further, the chamber 201 includes a purge room 204 which temporarilyholds the wafer W introduced into the chamber to purge it, a buffer room205 which holds the wafer W, and a transfer device 206 which is disposedbetween the purge room 204 and the buffer room 205 for transferring thewafer W from the purge room 204 to the buffer room 205. The purge room204 and the buffer room 205 are made to receive the wafer W in multipletiers.

In the purge room 204, a transit opening 207 for carrying the wafer Wfrom the wafer carrier 55 into the purge room 204 and a transit opening208 for carrying the wafer W from the purge room 204 to the transferdevice 206 are provided. Shutters 209 and 210 for opening and closingthe transit openings 207 and 208 are respectively provided in thetransit openings 207 and 208.

In the buffer room 205, a transit opening 211 for directly carrying thewafer W out to, for example, an in-stage (an illustration of which isomitted) of the aligner 5 is provided. A shutter 212 for opening andclosing the transit opening 211 is also provided in the transit opening211.

When the wafer W is carried into the purge room 204 from the wafercarrier 55, it is first purged in the purge room 204 under a reducedpressure. The aforesaid provision of the purge room 204 can prevent thecontamination of atmospheres in the transfer device 206 and the bufferroom 205.

Next, the wafer W is delivered from the purge room 204 to the bufferroom 205 by the transfer device 206, and the wafer W in the buffer room205 is carried from the buffer room 205 into the aligner 5.

Thus, according to this embodiment, such a structure that the wafer Wdelivered from the processing station 3 and to be transferred to thealigner 5 is temporarily held in the chamber 201 in which the atmosphereis controlled is given, which makes it possible to suppress thevariation with time of a resist before exposure and to prevent a changein a property of the resist. As a result, the uniformity of line widthcan be improved.

Fourth Embodiment

Next, the fourth embodiment in which the present invention is applied toa substrate coating and developing system will be explained.

First, a conventional example will be explained with reference to FIG.28. As shown in FIG. 28, a cassette C housing 25 substrates, forexample, semiconductor wafers W is carried into a cassette stage 301 ofa cassette station A1. A processing station A2 is connected to thecassette station A1, and further, an aligner not illustrated isconnected to the processing station A2 via an interface station A3.

The wafer W inside the cassette C on the cassette stage 301 is taken outby a delivery arm 311 and sent to a coating unit 313 through a deliverysection of a shelf unit 312 to be coated with the resist. Subsequently,the wafer W is transferred by the route of a wafer transfer means 314→adelivery section of a shelf unit 315→the interface station A3→thealigner to be exposed. The wafer W subjected to the exposure istransferred to the processing station A2 by the reverse route, developedin a developing unit provided in the lower tier of the coating unit 313but not illustrated, and then transferred by the route of the wafertransfer means 314→the delivery section of the shelf unit 312→thecassette C.

It should be noted that each shelf of the shelf units 312 and 315 isstructured as a heating section, a cooling section, the delivery sectionof the wafer W, a hydrophobic processing section or the like, and beforethe aforesaid resist coating and developing processing, heatingprocessing and cooling processing are performed in this order in theshelf units 312 and 315 in order to perform the resist coating or thelike at a predetermined temperature. Incidentally, the numeral 316denotes the delivery arm for delivering the wafer W between theprocessing station A2 and the aligner.

Further, a processing area composed of the coating unit 313 and thedeveloping unit and a transfer area in which the wafer transfer means314 is disposed are partitioned off in the processing station A2, and anatmosphere in a clean room is taken in and the air the temperature andthe humidity of which are adjusted at predetermined temperature andhumidity is sent into the processing area, whereby the area have, so tospeak, an atmosphere which is adjusted with high accuracy.

It should be noted that a chemically amplified resist forms an acid bybeing exposed, and the acid is diffused by heating processing to act asa catalyst which decomposes a basic resin as a main component of aresist material and changes its molecular structure to its molecularstructure to make the basic resin soluble in a developing solution.Therefore, when this kind of resist is used, the wafer W after theexposure is heated to a predetermined temperature, for example, in theheating section of the shelf unit 315, and subsequently, cooled to apredetermined temperature in the cooling section of the same shelf unit315 in order to inhibit a solubilization reaction (a resolution reactionof the resist) to the developing solution due to the acid, and then,coated with the developing solution in the developing unit.

However, in the chemically amplified resist, since the resolutionreaction of the resist progresses at a temperature around roomtemperature, changes in the temperature of the transfer area and in thetransfer time influence developing line width significantly when thewafer W is transferred by the route of the aligner→the heating section,which causes the disadvantage that the developing line width changes dueto these changes, which is noticeable particularly in an acetal-serieschemically amplified resist.

Thereby, the transfer time of the aligner→the heating section iscontrolled to make the progress of the resolution reaction of the resistduring the transfer uniform so that the uniformity of the developingline width can be secured, but still, there are variations in developingline width.

The fourth embodiment is to deal with the aforesaid disadvantages.

FIG. 17 is a schematic plane view of this embodiment, and FIG. 18 is aperspective view showing an interior seen through, in which S1 is acassette station, S2 is a processing station for performing coatingprocessing of a resist, developing processing, and the like for thewafer W, S3 is an interface station, and S4 is an aligner.

The cassette station S1 includes a cassette stage 321 as a mountingsection on which a wafer cassette (hereinafter referred to as a“cassette”) 322 such as four substrate cassettes housing a plurality ofsubstrates, for example, 25 wafers W is mounted, and a delivery arm 323as a delivery means for delivering the wafer W between the cassette 322on the cassette stage 321 and the processing station S2. The deliveryarm 323 is structured to be ascendable and descendable, movable in theX-direction and the Y-direction, and rotatable around a vertical axis.

Further, the processing station S2 includes, for example, two developingunits D (D1, D2), two coating units C (C1, C2), for example, three shelfunits R (R1, R2, R3) and, for example, one substrate transfer means MA,and is structured to deliver the wafer W between the cassette station S1and the interface station S3, and in the station S2, to performprocessing of coating the substrate with a resist solution, processingof developing the wafer W, and processing of heating and cooling thewafer W to predetermined temperatures before and after such processing.

In explanation of an example of a layout of the processing station S2like this, processing units U including the developing unit D, thecoating unit C and so on are provided in two tiers on the back side ofthe aforesaid delivery arm 323, for example, on the right side when, forexample, the back side is seen from the cassette station S1. That is,two developing units D1 and D2 as two developing processing sections aredisposed side by side in a direction almost perpendicular to thedirection of arrangement of the cassettes on the cassette stage 321 withthe developing unit D1 on the front side, and at the lower tiers ofthese developing units D1 and D2, two coating units C1 and C2 aredisposed side by side with the coating unit C1 on the front side.Incidentally, in the following explanation, the cassette station S1 sideis referred to as the front side and the aligner S4 side is referred toas the back side.

Moreover, on the left side of the processing units U as seen from thecassette station S1, the substrate transfer means MA which isstructured, for example, to be ascendable and descendable, movable rightand left and back and forth, and rotatable around a vertical axis isprovided to deliver the wafer W among the coating units C, thedeveloping units D and the shelf units R. Further, the shelf unit R1 isdisposed on the front side of the substrate transfer means MA as seenfrom the cassette station S1 side, the shelf unit R2 is disposed on theback side thereof, and the shelf unit R3 is disposed on the left sidethereof, respectively. It should be noted that in FIG. 18, the shelfunit R3 and the substrate transfer means MA are omitted for convenience.

In the aforesaid shelf units R1 and R3, as shown with the shelf unit R1as a representative in FIG. 19, heating sections 331 for heating thewafer W, cooling sections 332 for cooling the wafer W, a hydrophobicsection 333 for making a surface of the wafer W hydrophobic, a deliverysection 334 including a delivery table for delivering the wafer Wbetween the delivery arm 323 of the cassette station S1 and thesubstrate transfer means MA in the shelf unit R1, and an alignmentsection 335 for performing alignment of the wafer W in the shelf unit R1are vertically arranged.

The aforesaid heating section 331 is structured so that the wafer W isheated to a predetermined temperature by mounting the wafer W on asurface of a hot plate in which, for example, a heater is embedded, andthe aforesaid cooling section 332 is structured so that the wafer W iscooled to a predetermined temperature by mounting the wafer W on asurface of a chill plate in which, for example, a thermo module isembedded.

Further, in the aforesaid shelf unit R2, as shown in FIG. 20, CHPprocessing stations (Chilling Hot Plate Processing station) for heatingand subsequently cooling the wafer W and a delivery section 340including a delivery table for delivering the wafer W between a transferarm A which will be described later of the interface station S3 and thesubstrate transfer means MA are vertically arranged.

The aforesaid CHP station 304 includes, for example as shown in FIG. 21Ato FIG. 21D, a hot plate 341 as a heating section for heating the waferW and a chill plate 342 for cooling the wafer W, in which the wafer W isfirst mounted on the hot plate 341 to be heated to a predeterminedtemperature (refer to FIG. 21), subsequently, the wafer W is liftedfrom, for example, the hot plate 341 by, for example, a projecting pin343 and the chill plate 342 is moved to a position below the wafer W bya transfer means 344 to deliver the wafer W to the chill plate 342(refer to FIG. 21B and FIG. 21C), and thereafter, the chill plate 342 ismoved to a position by the side of the hot plate 341 with the wafer Wmounted thereon to cool the wafer W to a predetermined temperature (FIG.21D). Thus, the heating time is controlled by the delivery of the waferW between the hot plate 341 and the chill plate 342 in this processstation, thereby preventing an over-bake.

Next, in explanation of the developing unit D based on, for example,FIG. 22, the numeral 351 denotes a cup, and a spin chuck 352 which has afunction of vacuum suction is provided rotatably inside the cup 351. Thespin chuck 352 is structured to be ascendable and descendable by araising and lowering mechanism 353, and when it is positioned above thecup 351, the wafer W is delivered to an arm 361 which will be describedlater of the substrate transfer means MA.

Regarding the delivery of the wafer W, the wafer W on the arm 361 isdelivered to the spin chuck 352 on the upper side of the cup 351, towhich it is relatively raised from its lower side, and delivered fromthe spin chuck 352 side to the arm 361 by the reverse operationalsequences. The numeral 354 denotes a discharge nozzle of a processingsolution, the numeral 355 denotes a processing solution supply pipe, andthe numeral 356 denotes a supporting arm for moving the nozzlehorizontally.

The discharge nozzle 354 is structured to include a plurality of supplyholes which are arranged, for example, in a diameter direction of thewafer W, and the developing solution is discharged onto the surface ofthe wafer W on the spin chuck 352 from the discharge nozzle 354, and thedeveloping solution is heaped up on the wafer W by half rotating thespin chuck 352 so that a solution film of the developing solution isformed.

Further, the coating unit C has almost the same structure as thedeveloping unit D, whereas in the coating unit C, the discharge nozzle354 is structured to supply the processing solution onto, for example, apoint almost close to the center of the wafer W, and the resist solutionas the processing solution is dropped onto the surface of the wafer W onthe spin chuck 352 from the discharge nozzle 354, and the resistsolution is spread over to coat the wafer W by rotating the spin chuck352.

Moreover, the processing units U are spatially closed. Namely, as shownin FIG. 22, the developing unit D or the like is partitioned off fromother areas by a wall portion 357 and a partition wall 358 partitionsrespective sections such as the developing unit D1 and the coating unitC1, and a delivery port 350 is formed in the wall portion at a positioncorresponding to the arm 361 of the substrate transfer means MA in therespective sections such as the developing unit D1.

Furthermore, the air which is rid of impurities, adjusted at apredetermined temperature, for example, at 23° C. as a coatingtemperature of the developing solution and at a predetermined humidityis sent into respective sections partitioned off by the wall portion 357and the partition wall 358, whereby these areas have, so to speak,atmospheres which are adjusted with high accuracy.

Namely, for example, in the partitioned processing unit U, for exampleas shown in FIG. 22, a filter unit F1 is provided to cover the upperside thereof, and an atmosphere collected from the lower side of theprocessing unit U is exhausted to a plant exhaust system, while a partthereof is introduced to a filter device 359, and air cleaned by thefilter device 359 is blown out as a down-flowing air through theaforesaid filter unit F1 into each section.

The aforesaid filter unit F1 includes, for example, a filter forcleaning the air, and includes a chemical filter to which an acidiccomponent for removing alkali components in the air such as anammoniacal component and amine is added, a suction fan, and so on when achemically amplified resist is used. Further, the aforesaid filterdevice 359 includes an impurity removing section for removing theimpurities, a heating mechanism, a humidifying mechanism, a feedingsection for feeding the air and so on.

When the chemically amplified resist, for example, is used as the resistsolution, it is necessary to remove an alkali component because acatalytic reaction due to an acid which will be described later isinhibited if the alkali component such as a trace of ammonia included inthe air and the amine generated from a wall coating touches the acid onthe resist surface to deteriorate a shape of a pattern. Therefore, it isnecessary to prevent the alkali component from getting into thedeveloping processing atmosphere, and hence the processing unit isspatially closed to prevent an entrance of the alkali component from theoutside by using the chemical filter.

The aforesaid substrate transfer means MA includes, for example as shownin FIG. 23, the three arms 361 for holding the wafer W, a base table 362for supporting the arm 361 to be movable back and forth, a pair of guiderails 363 and 364 for supporting the base table 362 to be ascendable anddescendable, and it is structured to be movable back and forth,ascendable and descendable, and rotatable around a vertical axis byrotating these guide rails 363, 364 by a rotating drive section 365.

The interface station S3 is connected next to the processing station S2,and the aligner S4 for exposing the wafer W on which a resist film isformed is connected to the back side of the interface station S3. Theinterface station S3 includes a shelf unit R4 in which reactioninhibiting sections 307 for performing processing of inhibiting theprogress of a resolution reaction of a resist for the wafer W and thetransfer arm A for delivering the wafer W among the processing stationS2, the aligner S4 and the shelf unit R4, and is structured to deliverthe wafer W between the processing station S2 and the aligner S4 and toperform reaction retarding processing for the wafer W after exposure inthe station S3.

In explanation of an example of a layout of the interface station S3like this, the shelf unit R4 is provided, for example, on the right sidewhen, for example, the back side is seen from the cassette station S1side, and on the left side thereof, the transfer arm A which isstructured, for example, to be ascendable and descendable, movable rightand left and back and forth, and rotatable around a vertical axis isprovided to deliver the wafer W between the shelf unit R2 of theprocessing station S2, the shelf unit R4, and the aligner S4.

The aforesaid reaction inhibiting section 307 inhibits the progress ofthe resolution reaction of the resist by cooling the wafer W to such anextent that dew formation does not occure, and, for example, by mountingthe wafer W on a surface of a chill plate 371 in which, for example, athermo module 370 is embedded as shown in FIG. 24, the wafer W is cooledto a predetermined temperature, for example, to such a temperature thatthe resolution reaction of the resist does not progress and the dewformation does not occur, for example, to about 10° C. to 15° C. Thechill plate 371 is housed in a case 372 in which a delivery port 375 ofthe wafer W is formed at, for example, a position corresponding to thearm of the transfer arm A, and further, a raising and lowering pin 373which is raised and lowered by a raising and lowering mechanism 374 isprovided to deliver the wafer W to the plate 371 in the chill plate 371.

The thermo module 370 of the aforesaid chill plate 371 is asemiconductor device which can transfer heat from a heat absorbing sideto a heat radiating side by the passage of direct current, and since acalorific value can be controlled by changing the amount of the passingcurrent, the temperature of the wafer W is thereby adjusted with highaccuracy in the reaction inhibiting section 307. In this example, atemperature/humidity indicator 370 b detects the temperature and thehumidity in, for example, the interface station S3 and a dew point iscalculated based on this temperature/humidity, whereby the temperaturesetting of the chill plate 371 is controlled by a controlling section370 a so that the temperature is not lower than the dew point.

The structure of the transfer arm A is the same as that of the aforesaidsubstrate transfer means MA except that an arm 376 for holding the waferW is one and that the arm 376 is structured to be movable in thedirection of arrangement of cassettes (the Y-direction) of the cassettestation S1. For example, in the transfer arm A, the rotating drivesection 365 is movable along a guide rail 377 which is provided in theY-direction, and thus the arm 376 is structured to be movable in the X-and the Y-direction, to be ascendable and descendable, and rotatablearound the vertical axis.

Moreover, the interface station S3 is spatially closed. Namely, forexample, as in FIG. 25, it is partitioned off from other areas by a wallportion 378, and the delivery port 379 is formed in the wall portion 378at a position corresponding to the arm 376 of the transfer arm A.

Further, in the interface station S3, a filter unit F2 which includes,for example, a filter for cleaning air, and when the chemicallyamplified resist is used, includes the chemical filter to which theacidic component for removing alkali components in the air such as theammoniacal component and the amine is added, the suction fan, and so onis provided to cover the upper side thereof, and the cleaned air isblown out as down-flowing air through the filter unit F2.

Next, the operational sequence of the above-described embodiment will beexplained. First, an automatic transfer robot (or an operator) carriesthe cassette 322 housing, for example, the 25 wafers W onto the cassettestage 321, and the wafer W is taken our of the cassette 322 by thedelivery arm 323 to be placed in the delivery section 334 of the shelfunit R1 of the processing station S2.

The wafer W is transferred by the route of the substrate transfer meansMA→the hydrophobic section 333 of the shelf units R1, R3→the substratetransfer means MA→the cooling section 332 of the shelf units R1, R3→thesubstrate transfer means MA→the coating unit C, and after the surface ofthe wafer is made hydrophobic, it is cooled to a predeterminedtemperature to be subjected to temperature adjustment, and coated withthe resist solution at a predetermined temperature, for example, at 23°C. in the coating unit C.

The wafer W thus coated with the resist solution is transferred by theroute of the substrate transfer means MA→the heating section 331 of theshelf units R1, R3→the substrate transfer means MA→the cooling section332 of the shelf units R1, R3 to be subjected to temperature adjustment,and subsequently transferred by the route of the substrate transfermeans MA→the delivery section 340 of the shelf unit R2→the transfer armA of the interface station S3→the aligner S4 to be exposed.

The wafer W after the exposure is transferred by the route of thealigner S4→the transfer arm A of the interface station S3→the reactioninhibiting section 307 of the shelf unit R4, and in this reactioninhibiting section 307, the wafer W is delivered onto the surface of thechill plate 371 by the joint action of the raising and lowering pin 373and the transfer arm A to be mounted on the chill plate 371 which ispreviously set to a predetermined temperature for more than apredetermined time, so that the wafer W undergoes cooling processing tosuch a temperature as inhibits the progress of the resolution reactionof the resist does and does not cause dew formation, for example, toabout 10° C. to 15° C.

In explanation of the chemically amplified resist, as shown in FIG. 26Ato FIG. 26C, this resist includes a basic resin 381 as a main component,a protective group 382 for suppressing dissolution of the basic resin381 in the developing solution, and a photoacid generator 383, and has aproperty that the entire area to be exposed is exposed with a smallamount of an exposing energy.

With this kind of resist, for example as shown in FIG. 26A, an acid 384is generated from the photoacid generator 383 by exposure, andthereafter, as shown in FIG. 26B, the acid 383 cleaves the protectivegroup 382 from the basic resin 381 to make it soluble in the alkalinesolution by using thermal energy by heating processing. Next, the acid384 cleaves another protective group 382, and hence this reaction occurslike a chain reaction. Subsequently, this chain reaction is stopped bycooling processing, and thereafter, as shown in FIG. 26C, apredetermined pattern is formed in developing processing by removing anarea which becomes soluble in the alkaline solution by the chainreaction. In FIG. 26A to FIG. 26C, the numeral 385 is a substrate, thenumeral 386 is a resist and the numeral 387 is a mask on which thepredetermined pattern is formed.

In the resist like this, since the acid 384 which is generated byexposure acts as a catalyst, the resolution reaction of the resist (thereaction of cleaving the protective group 382 from the basic resin 381)progresses immediately after the exposure, although the progress isslow. However, the progressing speed of the resolution reaction dependson the temperature, and the progressing speed becomes considerably slowat the temperature which is lower than room temperature and is in suchan extent that dew formation does not occur, for example, about 10° C.to 15° C., which makes it possible to inhibit the progress of theresolution reaction. Therefore, by cooling the wafer W after theexposure to about 10° C. to 15° C. in the reaction inhibiting section307, the progress of the resolution reaction of the resist can beinhibited. Incidentally, the reason why a cooling temperature of thewafer W in the reaction inhibiting section 307 is set so as not to causedew formation is to prevent ununiform resolution progress and developingline width due to the acid 384 at the interface with the resist (theacid 384 near the surface thereof) being absorbed into the resistsolution if dew water adheres to the surface of the wafer W.

The wafer W which is thus cooled to a predetermined temperature istransferred by the route of the transfer arm A in the interface stationS3→the delivery section 340 of the shelf unit R2 of the processingstation S2→the substrate transfer means MA→the CHP process station 304of the shelf unit R2→the substrate transfer means MA→the developing unitD to be subjected to temperature adjustment by being heated to apredetermined temperature by the hot plate 341 and then cooled to apredetermined temperature by the chill plate 342 of the CHP processstation 304, and then the wafer W undergoes developing processing in thedeveloping unit D at a predetermined temperature, for example, at 23° C.which is the coating temperature of the developing solution.

Here, in this example, the heating processing is performed by cleavingthe protective group 382 from the resin 381 by the acid 384 on the hotplate 341 of the CHP process station 304 to make it soluble in thealkaline solution, and the cooling processing is performed to stop thechain reaction on the chill plate 342.

Subsequently, the wafer W is transferred by the route of the substratetransfer means MA→the heating section 331 of the shelf units R1, R3→thesubstrate transfer means MA→the cooling section 332 of the shelf unitsR→the substrate transfer means MA→the delivery section 334 in the shelfunits R→the delivery arm 323, and the wafer W which is heated to apredetermined temperature and then cooled to a predetermined temperatureis returned back, for example, into the original cassette 322 throughthe delivery section 334.

In the processing station S2, the wafer W is successively sent to thedelivery section 334 of the shelf unit R1, and then transferred by theroute of the vacant hydrophobic section 333→the vacant cooling section332 in the shelf units R1, R3→the vacant coating unit C→the vacantheating section 331 in the shelf units R1, R3→the vacant cooling section332 in the shelf units R1, R3→the interface station S3, and the wafer Wafter the exposure should be transferred by the route of the vacantreaction inhibiting section 307 of the shelf unit R4 in the interfacestation S3→the vacant CHP process station 304 of the shelf unit R2 inthe processing station S2→the vacant developing unit D→the vacantheating section 331 of the shelf units R1, R3→the vacant cooling section332 of the shelf units R1, R3→the delivery section 334 of the shelf unitR1.

According to the above embodiment, the wafer W is cooled to such atemperature as does not cause dew formation in the reaction inhibitingsection 307 after the exposure, which makes it possible to enhance theuniformity of the developing line width. That is, the wafer W exposed inthe aligner S4 is cooled to a predetermined temperature in the reactioninhibiting section 307, but the transfer time of the aligner S4→thereaction inhibiting section 307 is constant, and hence the resolutionreaction of the resist progresses to the almost same extent during thetransfer.

Further, since the wafer W is cooled to such an extent that the dewformation does not occur and the progress of the resolution reaction ofthe resist is inhibited in the reaction inhibiting section 307, theprogress of the resolution reaction of the wafer W therein is almostinhibited. Therefore, when the wafer W is made to wait in the reactioninhibiting section 307 for the transfer to the CHP process station 304which is a next process, the extent of the progress of the resolutionreaction becomes almost the same when the wafer W is transferred to theCHP process station 304. Thus, heating processing is performed for thewafer W of the same condition at all times on the hot plate 341 of theunit 304 so that the extent of the progress of the resolution reactionis made to be almost the same also in the hot plate 341, which makes itpossible to prevent an occurrence of variations in developing line widthand to enhance the uniformity of the developing line width.

In the above-described embodiment, the reaction inhibiting section 307may be structured to cool the wafer W by circulating a refrigerant inthe chill plate 371, or may be structured, for example, as shown in FIG.27. In this example, shelves 391 for mounting the wafer W in multipletiers are provided in a processing room 390 which is partitioned fromthe surroundings and sealed, and a gas having a predeterminedtemperature is supplied into the processing room 390, to thereby adjustthe temperature to such an extent that the progress of the resolutionreaction of the resist is inhibited and that dew formation does notoccur.

In FIG. 27, the numeral 392 denotes a storage tank of the gas to besupplied into the processing room 390, and the numeral 393 denotes anadjusting section for adjusting the gas from the storage tank 392 to apredetermined temperature and thereafter sending it into the processingroom 390. In this example, the temperature of the gas adjusted in theadjusting section 393 is controlled by a controlling section 395 basedon the temperature in the processing room 390 detected by a temperaturedetecting section 394. Further, as the gas to be supplied into theprocessing room 390, air, an inert gas such as nitrogen, a mixed gas ofthe air and the inert gas or the like and so on can be used.

Moreover, in the above example, the reaction inhibiting section 307controls the temperature of the wafer W, but the progress of theresolution reaction of the resist can be inhibited by controlling themoisture amount adhering to the wafer W. Namely, the acetal-serieschemically amplified resist has a property that it requires a humidityof about 45% in the resolution reaction of the resist, and theresolution reaction hardly occurs when the humidity is not enough.Therefore, by lowering the humidity inside the reaction inhibitingsection 307 to, for example, about 20% or less to obtain a low humiditycondition, and by making the wafer W wait therein for more than apredetermined time, the moisture amount adhering to the wafer W is madesmaller than the moisture amount adhering to the wafer W when it istransferred into the reaction inhibiting section 307 so that theprogress of the resolution reaction of the resist can be inhibitedconsiderably.

In concrete, in the reaction inhibiting section 307 shown in FIG. 24, itcan be structured so that the gas the humidity of which is adjusted inthe adjusting section is supplied from the storage tank into the case,and that the temperature of the gas which is adjusted in the adjustingsection is controlled by the controlling section based on the humidityin the case. As the gas supplied into the case, air, an inert gas suchas nitrogen, a mixed gas of the air and the inert gas or the like and soon can be used. Further, in the reaction inhibiting section 307 shown inFIG. 27, it can be structured so that the humidity of the gas which isadjusted in the adjusting section 393 is controlled by the controllingsection 395 based on the humidity in the processing room 390 detected bythe humidity detecting section.

Moreover, in the reaction inhibiting section, the temperature control ofthe wafer W and the control of the adherent moisture amount can beperformed in combination, in which case the higher uniformity ofdeveloping line width can be secured because the progress of theresolution reaction of the resist can be further inhibited.

The reaction inhibiting section 307 can be installed not only in theinterface station S3, but also inside the processing station S2, butwhen the temperature and the humidity in the transfer area between thealigner S4 and the reaction inhibiting section 307 are easy to change,the resolution reaction of the resist during the transfer progressessimilarly when the transfer time is shorter, and hence it is preferableto install the reaction inhibiting section 307 in the interface stationS3, and it is more preferable to install it near the aligner S4.

Furthermore, the temperature setting of the chill plate 371 of thereaction inhibiting section 307 may be set by the controlling section sothat the temperature higher by a predetermined temperature range, forexample, 1° C. to 3° C., than the dew point which is calculated by thedetected temperature and humidity may be set as an optimum value, inwhich case the predetermined temperature range can be changed based onthe type of the resist. Further, the cooling temperature may becalculated based on the temperature and humidity in the atmosphere sothat a relative humidity (value determined by the cooling temperaturewith respect to the moisture amount in the atmosphere) becomes 85%±5%,and based on this temperature, the temperature of the chill plate 371may be controlled by the predetermined temperature range. Furthermore, acontrolling temperature range of the chill plate 371 may be previouslyset, and when this temperature range does not fall within thepredetermined temperature range calculated by the dew point and therelative humidity, the controlling temperature range of the chill plate371 may be controlled to correct it.

In the present invention described above, an anti-reflection film may beformed on the surface of the wafer W before coating the resist, insteadof the hydrophobic processing. In this case, since the wafer W is cooledto a predetermined temperature before the processing of forming theanti-reflection film, for example, a unit for forming theanti-reflection film is added to the processing unit U, and when thewafer W is transferred to the unit for forming the anti-reflection filmbased on the temperature of the transfer area, the temperature of thecooling section 304 is controlled based on the temperature of thetransfer area so that the temperature of the wafer W reaches atemperature for performing the processing.

Further, as shown in FIG. 29, a beam 701 scans on the wafer W in dueorder in the aligner S4. Therefore, a time lag occurs in a reactiondepending on the area of the wafer W. In the reaction inhibiting section307, as shown in FIG. 30, the aforesaid time lag can be avoided when thecooling extent is changed according to the area of the wafer W. Morespecifically, for example, the area where the beam 701 is emittedearlier in time in the aligner S4 may be cooled to a lower temperature.Further, the aforesaid time lag can be also avoided when the timing ofthe cooling is changed according to the area of the wafer W. Inconcrete, for example, the area where the beam 701 is emitted earlier intime in the aligner S4 may be cooled earlier.

Incidentally, the anti-reflection film is formed to prevent thereflection which occurs at the lower side of the resist in exposure whenthe chemically amplified resist is used. Further, in the presentinvention, the substrate is not limited to the wafer, and may be a glasssubstrate for a liquid crystal display.

As described above, according to the present invention, the substrate istransferred from the aligner to the heating section with the resolutionreaction of the resist being inhibited, which makes it possible toenhance the uniformity of the developing line width.

Fifth Embodiment

Next, the fifth embodiment in which the present invention is applied toa substrate coating and developing system will be explained.

FIG. 31 is a schematic plane view of this embodiment, FIG. 32 is aperspective view showing an interior seen through, in which S1 is acassette station, S2 is a processing station for performing a coatingprocessing of a resist, a developing processing, and the like for thewafer W, S3 is an interface station, and S4 is an aligner.

The cassette station S1 includes a cassette stage 421 as a mountingsection on which a wafer cassette (hereinafter referred to as a“cassette”) 422 such as four substrate cassettes housing a plurality ofsubstrates, for example, 25 wafers W is amounted, and a delivery arm 423as a delivery means for delivering the wafer W between the cassette 422on the cassette stage 421 and the processing station S2. The deliveryarm 423 is structured to be ascendable and descendable, movable in theX-direction and the Y-direction, and rotatable around a vertical axis.

Further, the processing station S2 includes, for example, two developingunits D (D1, D2) as two developing processing sections, two coatingunits C (C1, C2) and, for example, three shelf units R (R1, R2, R3), forexample, one substrate transfer means MA, and is structured to deliverthe wafer W between the cassette station S1 and the interface stationS3, and in the station S2, to perform processing of coating the wafer Wwith a resist solution, processing of developing the wafer W, andprocessing of heating and then cooling the wafer W to a predeterminedtemperature before and after these processing.

In explanation of an example of a layout of the processing station S2like this, processing units U including the developing unit D, thecoating unit C and so on are provided with two tiers on the back side ofthe aforesaid delivery arm 423, for example, on the right side when, forexample, the back side is seen from the cassette station S1. That is,two developing units D1, D2 are disposed side by side in a directionalmost perpendicular to the direction of arrangement of the cassettes onthe cassette stage 421 with the developing unit D1 on the front side,and in the lower tiers of these developing units D1 and D2, two coatingunits C1 and C2 are provided side by side with the coating unit C1 onthe front side. Incidentally, in the following explanation, the cassettestation S1 side is referred to as the front side and the aligner S4 sideis referred to as the back side.

Moreover, on the left side of the processing units U as seen from thecassette station S1, the substrate transfer means MA which isstructured, for example to be ascendable and descendable, movable rightand left and back and forth, and rotatable around a vertical axis isprovided to deliver the wafer W among the coating units C, thedeveloping units D, and the shelf units R. Further, the shelf unit R1 isdisposed on the front side of the substrate transfer means MA as seenfrom the cassette station S1 side, the shelf unit R2 is disposed on theback side thereof, and the shelf unit R3 is disposed on the left sidethereof, respectively. It should be noted that in FIG. 32, the shelfunit R3 and the substrate transfer means MA are omitted for convenience.

As shown with the shelf unit R1 in FIG. 33 and the shelf unit R2 in FIG.34, heating sections 431 for heating the wafer W, cooling sections 432for cooling the wafer W, a hydrophobic section 433 for making thesurface of the wafer W hydrophobic in the shelf units R1 and R3, adelivery section 434 including a delivery table for delivering the waferW between the delivery arm 423 of the cassette station S1 and thesubstrate transfer means MA in the shelf unit R1, and for delivering thewafer W between the transfer arm A of the interface station S3 whichwill be described later and the substrate transfer means MA in the shelfunit R2, and an alignment section 435 for performing alignment of thewafer W in the shelf unit R1 are vertically arranged in the aforesaidshelf units R (R1, R2, R3).

The aforesaid heating section 431 is structured so that the wafer W isheated to a predetermined temperature by mounting the wafer W on asurface of a hot plate in which, for example, a heater is embedded, andthe aforesaid cooling section 432 is structured so that the wafer W iscooled to a predetermined temperature by mounting the wafer W on asurface of a chill plate in which, for example, a thermo module isembedded.

In explanation of the aforesaid developing unit D based on, for example,FIG. 35, in which the numeral 441 denotes a cup, and a spin chuck 442which has a function of vacuum suction is provided rotatably inside thecup 441. The spin chuck 442 is structured to be ascendable anddescendable by a raising and lowering mechanism 443, and when it ispositioned above the cup 441, the wafer W is delivered to an arm 451which will be described later of the aforesaid substrate transfer meansMA.

Regarding the delivery of the wafer W, the wafer W on the arm 451 isdelivered to the spin chuck 442 on the upper side of the cup 441, towhich it is relatively raised from its lower side, and delivered fromthe spin chuck 442 side to the arm 451 by the reverse operationalsequences. The numeral 444 denotes a discharge nozzle of a processingsolution, for example, a developing solution, the numeral 445 denotes aprocessing solution supply pipe, and the numeral 446 denotes asupporting arm for moving the nozzle horizontally.

The aforesaid discharge nozzle 444 is structured to include a pluralityof supply holes which are arranged, for example, in a diameter directionof the wafer W, and the developing solution is discharged onto thesurface of the wafer W on the spin chuck 442 from the discharge nozzle444, and the developing solution is heaped up on the wafer W by halfrotating the spin chuck 442 so that a solution film of the developingsolution is formed.

Further, the coating unit C has almost the same structure as thedeveloping unit D, whereas in the coating unit C, the discharge nozzle444 is structured to supply the developing solution onto, for example, apoint almost close to the center of the wafer W, and the resist solutionis dropped onto the surface of the wafer W on the spin chuck 442 fromthe discharge nozzle 444, and the resist solution is spread over to coatthe wafer W by rotating the spin chuck 442.

Moreover, the processing units U are spatially closed. Namely, as shownin FIG. 35, the developing unit D or the like is partitioned off fromother areas by a wall portion 447 and a partition wall 448 partitionsrespective sections such as the developing unit D1 and the coating unitC1, and a delivery port 440 is formed in the wall portion 447 of eachsection such as the developing unit D1 at a position corresponding tothe arm 451 of the substrate transfer means MA.

Furthermore, air which is rid of impurities, adjusted at a predeterminedtemperature, for example, at 23° C. as a coating temperature of thedeveloping solution and at a predetermined humidity is sent intorespective sections which are partitioned off by the wall portion 447and the partition wall 448, whereby these areas have, so to speak, theatmosphere which is adjusted with high accuracy.

Namely, for example, in the partitioned processing unit U, for exampleas shown in FIG. 35, a filter unit F1 is provided to cover the upperside thereof, and the atmosphere collected from the lower side of theprocessing unit U is exhausted to a plant exhaust system, while a partthereof is introduced to a filter device 449, and the air cleaned by thefilter device 449 is blown out as down-flowing air through the aforesaidfilter unit F1 into each section.

The aforesaid filter unit F1 includes, for example, a filter forcleaning air, and when a chemically amplified resist is used, includes achemical filter to which an acidic component for removing alkalicomponents in the air such as an ammoniacal component and an amine isadded, a suction fan, and so on. Further, the aforesaid filter device449 includes an impurity removing section for removing impurities, aheating mechanism, a humidifying mechanism, a feeding section forfeeding the air, and so on.

When the chemically amplified resist, for example, is used as the resistsolution, it is necessary to remove the alkali component because acatalytic reaction due to an acid which will be described later isinhibited if the alkali component such as a trace of ammonia included inthe air and the amine generated from a wall coating touches the acid onthe resist surface to deteriorate a shape of a pattern. Therefore, it isnecessary to prevent the alkali component from getting into thedeveloping processing atmosphere, and hence the processing unit isspatially closed to prevent an entrance of the alkali component from theoutside by using the chemical filter.

The aforesaid substrate transfer means MA is the same as the one shownin, for example, FIG. 23.

The interface station S3 is connected next to the processing station S2,and the aligner S4 as an exposure section for exposing the wafer W onwhich a resist film is formed is connected to the back side of theinterface station S3. The interface station S3 includes a shelf unit R4in which CHP process stations (chilling Hot Plate Processing station)406 for heating and thereafter cooling the wafer W are provided inmultiple tiers and the transfer arm A for delivering the wafer W amongthe shelf unit R4, the shelf unit R2 of the processing station S2, andthe aligner S4, and is structured to deliver the wafer W between theprocessing station S2 and the aligner S4 and in the station S3, totransfer the wafer W after exposure to the CHP process station 406 witha resolution reaction of the resist being inhibited, where heatingprocessing for facilitating the resolution of the resist and the coolingprocessing for stopping the resolution reaction of the resist areperformed.

In explanation of an example of a layout of the interface station S3like this, the shelf unit R4 is provided, for example, on the left sidewhen, for example, the back side is seen from the cassette station S1,and on the right side thereof, the transfer arm A which is structured,for example, to be ascendable and descendable, movable right and leftand back and forth, and rotatable around a vertical axis is provided.

The aforesaid CHP process station 406 includes, for example as shown inFIG. 36A to FIG. 36D, a hot plate 461 as a heating section for heatingthe wafer W and a chill plate 462 as a cooling section for cooling thewafer W in a processing room with a carrying in/out port 460 formedtherein, in which the wafer W is first mounted on the hot plate 461 tobe heated to a predetermined temperature (FIG. 36A), then, the wafer Wis lifted from the hot plate 461 by, for example, a projecting pin 463and the chill plate 462 is moved to a position on the lower side of thewafer W by a transfer means 464 to deliver the wafer W to the chillplate 462 (FIG. 36B, FIG. 36C), and thereafter, the chill plate 462 ismoved to a side position of the hot plate 461 with the wafer W mountedthereon to cool the wafer W to a predetermined temperature (FIG. 36D).Thus, the heating time is controlled by the delivery of the wafer Wbetween the hot plate 461 and the chill plate 462 in this unit, therebypreventing an over-bake.

The structure of the transfer arm A is the same as that of the substratetransfer means MA except that an arm 456 for holding the wafer W is oneand that the arm 456 is structured to be movable in the direction ofarrangement of the cassettes (the Y-direction) of the cassette stationS1. For example, in the transfer arm A, a rotating drive section 455 ismovable along a guide rail 457 which is provided in the Y-direction,whereby the arm 456 is structured to be movable in the X- and theY-direction, to be ascendable and descendable, and rotatable around thevertical axis.

Moreover, the interface station S3 is spatially closed. Namely, as shownin FIG. 37 and FIG. 38, it is partitioned off from other areas by a wallportion 471, and a delivery port 472 is formed in the wall portion 471at a position corresponding to the arm 456 of the transfer arm A.

In the interface station S3, the filter unit F2 which includes, forexample, a filter for cleaning air, and when the chemically amplifiedresist is used, includes the chemical filter to which the acidiccomponent for removing alkali components in the air such as theammoniacal component and the amine is added, the suction fan and so onis provided to cover the upper side thereof, and similarly to theprocessing unit U, the atmosphere collected from the lower side of theinterface station S3 is exhausted to the plant exhaust system, while apart thereof is introduced to a filter device 473, and the air cleanedby the filter device 473 is blown out as down-flowing air through theaforesaid filter unit F2 into each section.

The aforesaid filter device 473 includes an impurity removing sectionfor removing the impurities, a heating mechanism, a humidifyingmechanism, a feeding section for feeding air and so on, and thus the airwhich is rid of the impurities, adjusted at a predetermined temperature,for example, at such a temperature that the progress of the resolutionreaction of the resist is inhibited and that dew formation does notoccur, which is 10° C. to 15° C., and adjusted at a predeterminedhumidity is sent into the interface station S3.

Further, in the interface station S3, a partition wall 474 partitions anarea in which the shelf unit R4 is provided from an area in which thetransfer arm A is provided. In the partition wall 474, a delivery port475 of the wafer W is formed at a position corresponding to eachcarrying in/out port 460 of the wafer W of the aforesaid CHP processstations 406, and in this example, the carrying in/out port 460 and thedelivery port 475 are structured to be freely opened and closed byshutters 465 and 476, respectively, and the timing of the opening andclosing of the shutters 465, 476 is controlled by a controlling section477.

Next, the operational sequence of the above-described embodiment will beexplained. First, an automatic transfer robot (or an operator) carriesthe cassette 422 housing, for example, the 25 wafers W onto the cassettestage 421 and the wafer W is taken out the cassette 422 by the deliveryarm 423 to be placed in the delivery section 434 in the shelf unit R1 ofthe processing station S2.

The wafer W is transferred by the route of the substrate transfer meansMA→the hydrophobic section 433 of the shelf units R→the substratetransfer means MA→the cooling section 432 of the shelf units R→thesubstrate transfer means MA→the coating unit C, and after the surface ofthe wafer is made hydrophobic, it is cooled to a predeterminedtemperature to be subjected to temperature adjustment, and coated withthe resist solution at a predetermined temperature, for example, at 23°C. in the coating unit C.

The wafer W which is thus coated with the resist solution is transferredby the route of the substrate transfer means MA→the heating section 431of the shelf units R→the substrate transfer means MA→the cooling section432 of the shelf units R to be subjected to temperature adjustment, andsubsequently transferred by the route of the substrate transfer meansMA→the delivery section 434 of the shelf unit R2→the transfer arm A ofthe interface station S3→the aligner S4 to be exposed.

The wafer W after the exposure is transferred by the route of thealigner S4→the transfer arm A of the interface station S3→the CHPprocess station 406 of the shelf unit R4, in which it is first heated toa predetermined temperature on the hot plate 461 of the CHP processstation 406 and thereafter cooled to a predetermined temperature on thechill plate 462 to be subjected to temperature adjustment.

On this occasion, since the partition wall 474 partitions the transferarm A from the CHP process station 406, the shutter 465 of the CHPprocess station 406 to which the wafer W is transferred and the shutter476 of the delivery port 475 which corresponds thereto are first openedto transfer the wafer W to the hot plate 461 of the CHP process station406, then these shutters 465 and 476 are closed, and subsequently,predetermined processing is performed on the hot plate 461 and the chillplate 462. Then, the shutter 465 of the CHP process station 406 and theshutter 476 of the partition wall 474 are opened again to deliver thewafer W to the transfer arm A, and thereafter, these shutters 465 and476 are closed.

The present invention is characterized in that the temperature of thetransfer area of the wafer W which is from the aligner S4 to the heatingsection (the hot plate 461) for performing facilitating processing ofthe resolution reaction of the resist is adjusted at such a temperaturethat the progress of the resolution reaction of the resist is inhibitedand dew formation does not occur, for example, at about 10° C. to 15° C.Therefore, in this example, the temperature inside the interface stationS3 is adjusted at 10° C. to 15° C., and the CHP process station 406 isprovided inside the interface station S3.

In explanation of the chemically amplified resist, as shown in FIG. 40Ato FIG. 40C, this resist includes a basic resin 481 as a main component,a protective group 482 for suppressing dissolution of the basic resin481 in the developing solution, and a photoacid generator 483, and has aproperty that the entire area to be exposed is exposed with a smallamount of exposing energy.

With this kind of resist, for example as shown in FIG. 40A, an acid 484is generated from the photoacid generator 483 by exposure, andthereafter, as shown in FIG. 40B, the acid 483 cleaves the protectivegroup 482 from the basic resin 481 to make it soluble in the alkalinesolution by using thermal energy by heating processing. Next, the acid484 cleaves another protective group 482, and hence this reaction occurslike a chain reaction. Subsequently, this chain reaction is stopped bycooling processing, and thereafter, as shown in FIG. 40C, apredetermined pattern is formed in developing processing by removing anarea which becomes soluble in the alkaline solution by the chainreaction. In FIG. 40A to FIG. 40C, the numeral 485 is a substrate, thenumeral 486 is a resist, and the numeral 487 is a mask on which apredetermined pattern is formed.

In the resist like this, since the acid 484 which is generated by theexposure acts as a catalyst, the resolution reaction (the reaction ofcleaving the protective group 482 from the basic resin 481) progressesimmediately after the exposure, although the progress is slow. However,progressing speed of the resolution reaction depends on the temperature,and progressing speed becomes considerably slow at the temperature whichis lower than room temperature and at such a temperature as does notcause dew formation, for example, about 10° C. to 15° C., which makes itpossible to inhibit the progress of the resolution reaction.

Therefore, by transferring the wafer W after the exposure through thetransfer area the temperature of which is adjusted at about 10° C. to15° C., as described above, to the hot plate 461, the progress of theresolution reaction of the resist during the transfer can be inhibited.Incidentally, the reason why a cooling temperature of the wafer W in thetransfer area is set so as not to cause dew formation is that ununiformresolution progress and developing line width occur due to the acid 484at the interface with the resist (the acid near the surface thereof)being absorbed into the resist solution if dew water adheres to thesurface of the wafer W.

Here, in this example, the heating processing is performed by cleavingthe protective group 482 from the resin 481 by the acid 484 on the hotplate 461 of the CHP process station 406 to make it soluble in thealkaline solution, and the cooling processing is performed to stop thechain reaction on the chill plate 462.

The wafer W which is thus processed in a predetermined manner in the CHPprocess station 406 is transferred by the route of the transfer arm A ofthe interface station S3→the delivery section 434 of the shelf unit R2of the processing station S2→the substrate transfer means MA→thedeveloping unit D, and the wafer W undergoes developing processing inthe developing unit D at a predetermined temperature, for example, at23° C. as the coating temperature of the developing solution.

Subsequently, the wafer W is transferred by the route of the substratetransfer means MA→the heating section 431 of the shelf units R→thesubstrate transfer means MA→the cooling section 432 of the shelf unitsR→the substrate transfer means MA→the delivery section 434 of the shelfunit R1→the delivery arm 423, in which the wafer W which is temporarilyheated to a predetermined temperature and then cooled to a predeterminedtemperature is returned back, for example, into the original cassette422 through the delivery section 434.

In the processing station S2, the wafer W is successively sent to thedelivery section 434 of the shelf unit R1, and then transferred by theroute of the vacant hydrophobic section 433→the vacant cooling section432 of the shelf units R1, R2, R3→the vacant coating unit C→the vacantheating section 431 of the shelf units R1, R2, R3→the vacant coolingsection 432 of the shelf units R1, R2, R3→the interface station S3, andthe wafer W after the exposure should be transferred by the route of thevacant CHP process station 406 of the shelf unit R4 in the interfacestation S3→the vacant developing unit D of the processing station S2→thevacant heating section 431 of the shelf units R1, R2, R3→the vacantcooling section 432 of the shelf units R1, R2, R3→the delivery section434 of the shelf unit R1.

According to the above embodiment, the wafer W after the exposure istransferred to the heating section through the transfer area which iscooled to such an extent that dew formation does not occur, which makesit possible to enhance the uniformity of developing line width. That is,the wafer W which is exposed in the aligner S4 is transferred to theheating section through a predetermined transfer area, but the timerequired for the tranfer of the aligner S4→the heating section isconstant, and hence the resolution reaction of the resist during thetransfer progresses to the almost same extent.

On this occasion, the temperature of the transfer area is controlled tosuch an extent that dew formation does not occur on the wafer W, andsince the progress of the resolution reaction of the resist is inhibitedat the temperature like this, the progress of the aforesaid resolutionreaction of the wafer W is almost inhibited in the transfer area.Therefore, when the wafer W after the exposure is transferred to the CHPprocess station 406 which is a next process in this situation, theresolution reaction of the wafer W when transferred to the CHP processstation 406 progresses to the almost same extent. Thus, since heatingprocessing is performed for the wafer W of the same condition at alltimes, the above resolution reaction progresses to the almost sameextent also in the heating processing, so that variations in developingline width can be suppressed and the uniformity of developing line widthcan be enhanced.

Further, in this example, since the CHP process station 406 is providedin the interface station S3, the transfer area of the aligner S4→theheating section is inside the interface station S3. Here, a capacity ofthe interface station S3 is comparatively smaller than that of theprocessing station S2, and hence the transfer area of the aligner S4→theheating section becomes narrower, so that it is advantageous to fillthis transfer area with an atmosphere adjusted with high accuracy thetemperature and humidity of which are adjusted in terms of cost.

Moreover, in the interface station S3, since the partition wall 474partitions off the CHP process station 406 and the transfer arm A fromeach other, the area in which the transfer arm A is provided is lessinfluenced by the hot plate 461 of the CHP process station 406 in termsof temperature, which makes it possible to facilitate temperature andhumidity adjustment in the interface station S3.

In the present invention as described above, the shelf unit R4 whichincludes the CHP process stations 406 in multiple tiers may be providedin the processing station S2, as shown in FIG. 41. In this example, theaforesaid shelf unit R4 is provided on the right side of the back sideof the substrate transfer means MA as seen from the cassette station S1,and the shelf unit R2 is provided on the left side thereof, and it isstructured so that the wafer W is delivered by the substrate transfermeans MA between the shelf units R2 and R4, and that the wafer W isdelivered between the delivery section 434 of the shelf unit R2 and eachCHP process station 406 of the shelf unit R4 by the transfer arm A ofthe interface station S3.

The shelf unit R4 is, for example as shown in FIG. 42, partitioned offfrom other areas by the wall portion 481, and delivery ports 482 and 483are formed in the wall portion 481 at a position corresponding to thearm 361 of the substrate transfer means MA and at a positioncorresponding to the arm 456 of the transfer arm A, and the deliveryports 482 and 483 are structured to be freely opened and closed byshutters 484 and 485, respectively.

In each CHP process station 406, the filter unit F3 which includes, forexample, a filter for cleaning air, when the chemically amplified resistis used, includes the chemical filter to which the acidic component forremoving alkali components in the air such as the ammoniacal componentand the amine is added, the suction fan, or the like is provided tocover the upper side thereof, and the atmosphere collected from thelower side is exhausted, while a part thereof is introduced to a filterdevice 483, and the air cleaned by the filter device 483 is blown out asdown-flowing air through the aforesaid filter unit F3 into each section.

The aforesaid filter device 483 includes an impurity removing sectionfor removing impurities, a heating mechanism, a humidifying mechanism, afeeding section for feeding the air and so on, and thus, the air whichis rid of the impurities and adjusted at a predetermined temperature anda predetermined humidity is sent into the shelf unit R4, which makes itpossible to prevent alkaline components from getting into this area.

Further, the shelf unit R5 in the interface station S3 includes shelfsections in multiple tiers for making the wafer W on standby when thewafer W is transferred from the aligner S4 to the CHP process station406 of the shelf unit R4, and the shelf unit R5 is provided at aposition which is accessible by the transfer arm A. Also in thisexample, the temperature in the interface station S3 is adjusted at sucha temperature that the progress of the resolution reaction of the resistdoes is inhibited and that dew formation does not occur, for example, atabout 10° C. to 15° C. The other structure is the same as that of theaforesaid substrate processing apparatus, and the structure of each ofthe shelf units R is the same as above.

In this example, the wafer W after exposure is transferred to, forexample, the shelf section of the shelf unit R5 by the transfer arm A,where it waits for the transfer to the hot plate 461 of the CHP processstation 406, and is transferred to a predetermined CHP process station406 by the transfer arm A. Here, since the temperature in the interfacestation S3 is adjusted at about 10° C. to 15° C., the wafer W can betransferred from the aligner S4→the hot plate 461 with the resolutionreaction of the resist being inhibited, thereby enhancing the uniformityof developing processing.

Next, another example of the present invention will be explained withreference to FIG. 43 and FIG. 44. In this embodiment, instead ofadjusting the temperature inside the interface station S3, the wafer Wis transferred from the aligner S4 to the hot plate 461 of the CHPprocess station 406 while a gas which is adjusted at a predeterminedatmosphere is being supplied onto the wafer W in order to inhibit theresolution reaction of the resist.

In this example, the transfer arm A which is provided in the interfacestation S3 for transferring the wafer W between the processing stationS2 and the aligner S4 includes, for example shown in FIG. 43 and FIG.44, two arms 491 and 492, and the upper arm 491 is structured to be anexclusive arm for transferring the wafer W after exposure to the CHPprocess station 406, and the lower arm 492 is structured to be anexclusive arm for transferring the wafer W before exposure from theprocessing station S2 to the aligner S4.

A gas supply section 409 for supplying the gas adjusted at apredetermined atmosphere onto the wafer W which is supported on the arm491 is provided on the upper side of the upper arm 491, and a barrierplate 493 for preventing the gas adjusted at the predeterminedatmosphere from flowing onto the wafer W supported on the lower arm 492is provided under the upper arm 491.

The gas supply section 409 is in a shape of, for example, a flatcylinder, and attached to the back surface of a base table 452 (backsurface of the arm 451 in a movement direction) by a supporting arm 496so that a circular opening surface 495 provided with a plurality of gassupply holes 494 opposes the wafer W on the aforesaid arm 491. Theopening surface 495 of the aforesaid gas supply section 409 is set tohave a enough size capable of supplying air to the larger area than thewafer W supported on the arm 451.

In the gas supply section 409 like this, the gas, for example, air whichis rid of impurities and adjusted at a predetermined temperature, forexample, such a temperature that the progress of the resolution reactionof the resist is inhibited and that dew formation does not occur, forexample, about 10° C. to 15° C. and at a predetermined humidity issupplied from a filter device 497 through a gas supply pipe 498, wherebythe air is sent out onto the wafer W held on the arm 451 through the gassupply holes 494. The aforesaid filter device 497 includes an impurityremoving section for removing the impurities, a heating mechanism, ahumidifying mechanism, a feeding section for feeding the air and so on.Further, the aforesaid barrier plate 493 is set to have a enough sizecapable of covering the larger area than the wafer W supported on thearm 492 in order to prevent the gas supplied from the gas supply sectionfrom flowing onto the wafer W held on the lower arm 492.

In this kind of embodiment, the resolution reaction of the resist hardlyprogresses because the air which is adjusted at such a temperature thatdew formation on the wafer W does not occur when the wafer W istransferred from the aligner S4 to the CHP process station 406 by thetransfer arm A. Therefore, the wafer W can be transferred to the CHPprocess station 406 the progress of the resolution reaction of theresist being inhibied, which makes it possible to perform uniformprocessing while suppressing the occurrence of uneven developing.

In this example, as the gas supplied onto the wafer W, an inert gas suchas nitrogen, a mixed gas of air and the inert gas and so on can be usedbesides air. Further, the arm 491 for transferring the wafer W afterexposure may be provided on the lower side and the arm 492 fortransferring the wafer W before exposure can be provided on the upperside, and the gas supply section 409 may be structured, not to beintegrally attached to the transfer arm A, but to be separately providedto be able to supply the gas onto the wafer W held on the arm 491.

Further, this example in which the wafer W is transferred with the gasadjusted at a predetermined temperature being supplied thereon and theaforesaid example in which the temperature of the transfer area itselfis controlled may be combined, in which case the wafer W after exposurecan be transferred to the CHP process station 406 while furtherinhibiting the progress of the resolution reaction of the resist.

In the above example, the temperature in the transfer area or the likeis controlled, but the progress of the resolution reaction of the resistmay be inhibited by controlling the amount of moisture adhering to thewafer W. Namely, the acetal-based chemically amplified resist has aproperty that it requires a humidity of about 45% in the resolutionreaction of the resist, and the resolution reaction hardly occurs whenthe humidity is not enough. Therefore, by lowering the humidity insidethe transfer area to, for example, 20% or less to obtain a low humiditycondition the humidity of which is lower than that of the air, and bymaking the wafer W wait therein for more than a predetermined time, themoisture amount adhering to the wafer W is made smaller than themoisture amount adhering to the wafer W when it is transferred into theinterface station S3 after the exposure so that the progress of theresolution reaction of the resist can be inhibited considerably.

In concrete, it may be structured so that the gas the humidity of whichis adjusted in the filter device 473 is supplied into the interfacestation S3 and the gas supply section 409. As the gas supplied into theinterface station S3 or the like, air, an inert gas such as nitrogen, amixed gas of the air and the inert gas and so on can be used.

Moreover, in the transfer area of the wafer W, the temperature controlof the transfer area and the control of the moisture amount adhering tothe wafer may be performed in combination, in which case the higheruniformity of developing line width can be secured because the progressof the resolution reaction of the resist can be further inhibited.

The CHP process station 406 may be installed not only in the interfacestation S3, but also inside the processing station S2, but when thetemperature and the humidity in the transfer area between the aligner S4and the CHP process station 406 are easy to change, the resolutionreaction of the resist during the transfer progresses similarly when thetransfer time is shorter, and hence it is preferable to install the CHPprocess station 406 in the interface station S3, and it is morepreferable to install it near the aligner S4.

In the present invention described above, an anti-reflection film may beformed on the surface of the wafer W before coating the resist, insteadof the hydrophobic processing. Incidentally, the anti-reflection film isformed to prevent the reflection which occurs on the lower side of theresist in exposure when the chemically amplified resist is used.Further, in the present invention, the substrate is not limited to thewafer, and may be a glass substrate for a liquid crystal display.

As described above, according to the present invention, the substrate istransferred from the aligner to the heating section with the resolutionreaction of the resist being inhibited, which makes it possible toenhance the uniformity of developing line width.

Sixth Embodiment

In the embodiment shown in FIG. 43 and FIG. 44, the gas the temperatureand the humidity of which are adjusted is supplied from the gas supplyholes 494 of the gas supply section 409, but as shown in FIG. 45, aninert gas may be supplied from an inert gas tank 501 which containsnitrogen and the like toward the wafer W on an arm (tweezers) 491through gas supply holes (blast ports) 503 of a gas supply section (topcover) 502. The blast ports 503 may be provided, as shown in FIG. 45, tocorrespond to the shape of the tweezers 491, and may be provided, asshown in FIG. 46, to correspond to a circule which is the shape of thewafer W.

Being structured like this, it is prevented that the hydrolysis of aresist occurs due to moisture in air during the transfer of thesubstrate coated with the resist, and that the pattern resolution isinfluenced by being united with oxygen in the atmospheric air.

Incidentally, the temperature and the humidity of the inert gas may becontrolled as shown in FIG. 43 and FIG. 44.

Further, the inert gas is supplied as described above when the wafer Wis transferred from the resist coating unit to the heating processingunit, so that the gas can be supplied efficiently.

The disclosure of Japanese Patent Applications No.2000-24221 filed Feb.1, 2000, No. 2000-38509 filed Feb. 16, 2000, No. 2000-137509 filed May10, 2000 and No. 2000-133304 filed May 2, 2000 including specification,drawings and claims are herein incorporated by reference in itsentirety.

Although only some exemplary embodiments of this invention have beendescribed in detail above, those skilled in the art will readilyappreciated that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention.

1. A substrate processing apparatus, comprising: a reaction inhibitingsection, wherein the reaction inhibiting section controls an extent thatthe progress of the resolution reaction of a resist is inhibited withregard to the resist which is coated onto the substrate and is exposed,according to an area of the substrate; a heating section for heating thesubstrate processed in the reaction inhibiting section to progress theresolution reaction of the resist; a cooling section for cooling thesubstrate heated in the heating section to inhibit the progress of theresolution reaction of the resist; and a developing processing sectionfor performing coating processing of a developing solution for thesubstrate cooled in the cooling section; a temperature/humidityindicator detecting a temperature and a humidity in the reactioninhibiting section; and a controlling section configured to calculate adew point in the reaction inhibiting section based on the indicatedtemperature and humidity, and controlling the temperature in thereaction inhibiting section so that the temperature is not less than thedew point.
 2. A substrate processing apparatus, comprising: a firststation including a mounting section on which a substrate cassettehousing a plurality of substrates is mounted and a delivery means forreceiving and sending the substrate from/to the substrate cassettemounted on the mounting section; a second station, connected to thefirst station, for processing the substrate transferred by the deliverymeans; and an interface section for delivering the substrate between aprocessing station and an aligner for subjecting the substrate toexposure processing, wherein the second station includes: a heatingsection for heating the substrate to progress the resolution reaction ofthe resist, a cooling section for cooling the substrate heated in theheating section to inhibit the progress of the resolution reaction ofthe resist, and a developing processing section for performing coatingprocessing of a developing solution for the substrate; wherein theinterface section includes a reaction inhibiting section placed aposition nearer the aligner side, and has a chill plate for controllingan extent that the progress of the resolution reaction of a resist isinhibited with regard to the resist which is coated onto the substrateand is exposed, according to an area of the substrate; and wherein theapparatus has a temperature/humidity indicator detecting a temperatureand a humidity in the interface station; and a controlling sectionconfigured to calculate a dew point in the interface section based onthe indicated temperature and humidity, and controlling the temperatureof the chill plate so that the temperature in the interface section isnot lower than the dew point.
 3. The apparatus as set forth in claim 1,wherein the reaction inhibiting section inhibits the progress of theresolution reaction of the resist by cooling the substrate coated withthe resist and exposed so as not to cause dew formation.
 4. Theapparatus as set forth in claim 1, wherein the reaction inhibitingsection inhibits the progress of the resolution reaction of the resistby making an amount of moisture adhering to the substrate coated withthe resist and exposed smaller than an amount of moisture adhering tothe substrate when the substrate is transferred to the reactioninhibiting section.
 5. The apparatus as set forth in claim 4, whereinthe reaction inhibiting section makes the amount of the moistureadhering to the substrate smaller than the amount of the moistureadhering to the substrate when the substrate is transferred to thereaction inhibiting section by supplying a gas having a humidity lowerthan a humidity of air in an atmosphere in which the reaction inhibitingsection is placed.
 6. The apparatus as set forth in claim 1, wherein theresist is a chemically amplified resist, the resolution reaction ofwhich is progressed by an acid produced by exposure.
 7. The apparatusaccording to claim 2, wherein the reaction inhibiting section cools thearea of the substrate where a beam is emitted earlier in time in thealigner to a lower temperature.
 8. The apparatus according to claim 2,wherein the reaction inhibiting section cools the area of the substratewhere a beam is emitted earlier in time in the aligner earlier.
 9. Theapparatus according to claim 2, wherein the interface station has afirst area before exposure and a second area after exposure; wherein theapparatus comprises a partition plate shutting off the second area fromthe first area; and wherein the reaction inhibiting section is providedin the reaction inhibiting section.